1: Boot up your system, at the login screen press ctrl+alt+f1
2: At this point, login with your normal username and password then type "sudo su"
3: Type in your password, now you are in the root account
4: add a user using "adduser <username>" and fill in the blanks, replace <username> with your new user.
5: set a password using "passwd <username>"
6: add the user to the admin group: "adduser <username> admin"
7: press ctrl+alt+f7 and login, go to your home directory, press the up arrow, go into your old user directory and copy everything important