45 minutes - 2 hours
I was mistakingly unwinding an external mouse chord above my MBP. I dropped the bloody thing from about 3 inches and shattered my tracked.
The repair was fairly simple, I did have to go and buy a new Tri wing screwdriver to get the battery out (maplins in the UK seem to be th sonly high street store to stock any - Maybe by some on ebay in preparation!). The instructions were simple to follow and this replacement part as in and working with 20 minutes.
I skipped the process of removing the motherboard to gain access to the cable, that would have been a bit of a pain, I left the original ribbon (flat) cable in place, it runs underneath the main board and reappears so to replace it you have to remove every screw and the cooling fans.
There is a drop of glue holding the ribbon onto your existing trackpad and the new one. Some gentle pulling will remove it, just don't pull on an angle, so no 45 degree pulling!, as the ribbons are prone to tearing. Gently ease it up vertically away from the trackpad, it is stronger than you think and it will ease up.. simple.
Ifixit delivered to the UK with 48 hours. Superb service.