Manipulating TinyMCE content with jQuery
// get content from tinyMCE
    var content = tinyMCE.get('content').getContent();

    // manipulate content using js replace
    content = content.replace(/</?div>/gi, '');

    // send back to tinyMCE
    tinyMCE.get('content').setContent( content );

// get content from tinyMCE (it provides an html string)
    var content = tinyMCE.get('content').getContent();

    // make it into a jQuery object
    var $content = $(content);

    // manipulate the jquery object using jquery
    $content = $content.remove('a');

    // use a chained function to get its outerHTML
    content = $("<div />").append( $content.clone() ).html();

    // send back to tinyMCE
    tinyMCE.get('content').setContent( content );

var content = $('#content').html();

var content = $('#content').html('<span>NEW CONTENT</span>');

$content = $content.remove('a');

$content = $content.find('a').remove();