Home button for iPhone 4 was responding to push less and less over the past two months
Success! Although about 3/4 the way through the opening process it was a little daunting. However all is well and I'm delighted.
There may be advice on the site that I didn't read but my advice is to layout a white sheet, e.g., a pillow case, to layout all of the removed parts. (I used a towel but found the nap hid some of the smaller screws.) Then layout the parts in a way that represents the physical layout of the phone.
There are too many steps to remember where everything goes and the size of the screws is too small for the inexperienced to distinguish.