I highly recommend using a slew of refrigerator magnets to hold the screws for each step. I also used post its to label each step, making reassembly a snap.
In the end, I was able to successfully replace the jack, but they weren't kidding when they said it was difficult.
I can't believe it! My 3gs was totally dying all the time. This totally fixed it. The instructions were great and easy to follow.
My only criticism is that I wish they just wrote out reverse instructions for after the battery was installed, rather than having to scroll backwards.
But otherwise, I'm thrilled this site offered solution i could do myself!