This thread shows you how to validate your security information, for people who were having trouble with the hack.
So you can change all the templates at once, I went to styles and templates>search in templates>find and replace in templates, had it find the first line of text in the url above and replace it with that line and the add on line.
Make sure you click to permanently replace rather than test replace otherwise your changes won't stick.
Good luck and happy hack use!
BTW, this works on a 3.7 board guys.