I want to remove this Google Analytics block, using jQuery.
Try this:
var replacementDoneIn = $(document.body).text(); //remove Google Analytics document.write line
var regExMatch = /document\.write\(unescape/g;
var replaceWith = "//document.write";
var resultSet = replacementDoneIn.replace(regExMatch, replaceWith);
$("body").html(resultSet);
Hope that helps!