Lock/Power Button wouldn't function. Think of it as one of those useless snap buttons on your jeans, except the protruding part had worn away in less than 2 years.
Needed to take a couple breaks do to frustration and my lack of patience, but a success in the end.
When you take apart your phone, put the pieces on a sheet of paper labeled; step one, step two, etc. It makes it easier to put it back together.