how to modify an attribute of an annotation at runtime

@javax.servlet.sip.annotation.SipServlet
public class HelloSipWorld extends SipServlet {

    /**
     *
     */
    private static final long   serialVersionUID                = -9090594133332625693L;

    private static Log          logger                          = LogFactory.getLog(HelloSipWorld.class);

    private static String       newAppNameFromCallServiceString = "";

    static {
        System.out.println("INIT static HelloSipWorld. Vamos a escanear las anotaciones que tiene el fichero com.kurento.kmf.sip.package-info.java ");
        System.out.println("El proposito es poder coger el atributo name de la anotacion @CallService y aplicarselo al name de la anotacion @SipApplication.");
        try {
            Annotation[]  listaDeclaredAnnotations = HelloSipWorld.class.getPackage().getDeclaredAnnotations();
            for (Annotation a:listaDeclaredAnnotations) {
                System.out.println("ANOTACIONES DECLARADAS: " + a.toString());
            }


            //las anotaciones que hay en el mismo paquete donde esta alojado HelloSipWorld
            //annotations located in the same package than HelloSipWorld
            Annotation[] arrayAnotations = HelloSipWorld.class.getPackage().getAnnotations();
            for(Annotation a:arrayAnotations) {
                System.out.println("ANOTACIONES: " + a.toString());
            }

            Class<?> pClass = Class.forName("com.kurento.kmf.sip.package-info");
            System.out.println("pClass: " + pClass.toString());
            Field field = Class.class.getDeclaredField("annotations");
            field.setAccessible(true);

            //este es el mapa de anotaciones que tiene una determinada clase, en este caso, la clase package-info.java
            Map<Class<? extends Annotation>, Annotation> annotationsMap = (Map<Class<? extends Annotation>, Annotation>) field.get(pClass);
            System.out.println("LISTA DE ANOTACIONES: " + annotationsMap.toString());


            for (Annotation anotattion : arrayAnotations) {

                if (anotattion instanceof CallService) {
                    System.out.println("Procesando anotacion CallService...");
                    final CallService oldCallService = (CallService) HelloSipWorld.class.getPackage().getAnnotation(CallService.class);
                    System.out.println("Por defecto la anotacion CallService tiene como name = " + oldCallService.name());

                    //asigno a la variable temporal el name de la etiqueta CallService para poder asignarselo luego cuando procese la anotacion SipApplication
                    newAppNameFromCallServiceString = oldCallService.name();
                    System.out.println("Asignado nombre de la etiqueta CallService a la variable temporal. newAppNameFromCallServiceString: "
                            + newAppNameFromCallServiceString);
                    System.out.println("Se acabó de procesar la anotacion CallService...");
                }

                if (anotattion instanceof SipApplication) {
                    System.out.println("Procesando anotacion SipApplication...");
                    final SipApplication oldSipApplicationAnotation = (SipApplication) annotationsMap.get(SipApplication.class);
                    System.out.println("valor de oldSipApplicationAnotation: " + oldSipApplicationAnotation + " name: " + oldSipApplicationAnotation.name()); ;
                    Annotation newSipApplicationAnnotation = new SipApplication() {

                        @Override
                        public Class<? extends Annotation> annotationType() {
                            return oldSipApplicationAnotation.annotationType();
                        }

                        @Override
                        public String description() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.description();
                        }

                        @Override
                        public String displayName() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.displayName();
                        }

                        @Override
                        public boolean distributable() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.distributable();
                        }

                        @Override
                        public String largeIcon() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.largeIcon();
                        }

                        @Override
                        public String smallIcon() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.smallIcon();
                        }

                        @Override
                        public String mainServlet() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.mainServlet();
                        }

                        @Override
                        public String name() {

                            return newAppNameFromCallServiceString;
                        }

                        @Override
                        public int proxyTimeout() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.proxyTimeout();
                        }

                        @Override
                        public int sessionTimeout() {
                            // TODO Auto-generated method stub
                            return oldSipApplicationAnotation.sessionTimeout();
                        }
                    };
                    //modificamos el mapa de las anotaciones que tiene anotadas la clase que estoy escaneando. en este caso, package-info.java
                    annotationsMap.put(SipApplication.class, newSipApplicationAnnotation);
                    //asi no!
                    //final SipApplication modifiedSipApplicationAnotation = (SipApplication) HelloSipWorld.class.getAnnotation(SipApplication.class);
                    final SipApplication modifiedSipApplicationAnotation = (SipApplication) annotationsMap.get(SipApplication.class);
                    //esto en teoria provoca el cambio dentro del mapa annotationsMap, pq modifiedSipApplicationAnotation esta dentro del mapa y al llamar a name() le obligo a que coja el nuevo nombre!
                    System.out.println("nombre de modifiedSipApplicationAnotation: "  + modifiedSipApplicationAnotation.name());
                    System.out.println("Se acabó procesar la anotacion SipApplication...");

                }
            }

        } catch (Exception xcp) {
            xcp.printStackTrace();
        }
        System.out.println("END static HelloSipWorld...");
    }
....
//rest of methods of HelloSipWorld
}//end of HelloSipWorld


package-info.java file

/**
 *
 * Provides the way to instantiated a class that extends SipServlet without using a sip.xml
 *
 * @author Alonso Isidoro Roman (aroman@naevatec.com)
 * @version 1.0.0
 */
//La idea es poder coger el name de esta anotacion CallService y asignarsela a piñon al name de la anotacion SipApplication
@CallService(name ="My first kurento app")
@SipApplication(name = "default-name-sip-app", description = "default description of the SipApplication", displayName = "default-displayName")
package com.kurento.kmf.sip;

import javax.servlet.sip.annotation.SipApplication;
import com.kurento.kmf.sip.annotation.CallService;
//Important, this file is on the same package that HelloSipWorld.java