My problem was that the home button on the iPhone 4 stopped working/was not working reliably.
The repair was easy and smooth. I purchased all the tools needed before hand from iFixit. During the repair, on a pice of paper I labeled all of the steps and parts that came out from each step. That made it much easier to retrace my steps when going backwards.
Don't take out the 6 side screws and washers putting pressure on the front glass of the iPhone 4. Just loosen them, they are hard to get back in place. I took one out and it was the hardest part to put back in places.