I'd give myself 99% chance of success. There are good instructions here
http://ghonis2.ho8.com/rebelmod.html
But it is the 1% chance of f'ing it up that worries me...
I said I'd do in after the warrantee on the camera expired... Well that was in March!... Still taking good shots with the filter in, so still plenty out there to shoot with the camera as is...
Cheers