Firefox: How to uninstall XULRunner1.9.1

This problem is right at on the border of Malware and Software and a moderator can move this thread and delete this sentence if they find that it is misplaced.

I've been struggling for months with a google redirect issue and yesterday I thought I had it solved. These related pages helped me discover it was a corrupted firefox addon called XULrunner1.9.1.

http://support.mozilla.com/en-US/questions/749007

http://forums.majorgeeks.com/showthread.php?t=218175

Disabling it fixes the redirects, but I would prefer it be gone from my computer. The uninstall button is greyed out. A couple strange folders I have found might be relevant:

C:\Users\Owner\AppData\Local\Mozilla\Firefox\Profiles\f0kkuqb3.default\

This folder contains XUL.mfl, XPC.mfl, and urlclassifier3.sqlite, then offline and online caches. If I delete them, they reappear when I open firefox.

C:\Users\Owner\AppData\Local\{A26F6C68-0D83-4CDD-ABF5-0D8460789636}\chrome

This folder contains a folder called "content" and in that, overlay.xul and _cfg.

I have managed to delete XULrunner once (somehow) but it re-installs itself. What should I do to be rid of this thing?