Better Megaupload crack then this addon Rated 5 out of 5 stars

I found this website that may be of more help then you downloading that add-on, here is the site http://www.techtalkz.com/tips-n-tricks/4543-crack-megaupload-download-limits-bypass-country-slots-without-installing-toolbar.html
This site will tell you to have User Agent Switcher extension installed, and add a registery entry which will let you switch between your agent and the Megaupload agent that you add.