I had a lot of difficulty with this step. I did not have adhesive attached to my replacement part nor double sided adhesive tape to replace it. I was able to finish by screwing the power button bracket on - but very loosely. It took some doing, but I placed the ribbon between the button and bracket - making sure to line it up properly. After it looked right I tightened it down - but it took a few attempts to get correct. I need to do it again to take a picture of exactly how the ribbon attaches to the bracket and button - I had to look at a few other videos because I didn't pay close attention during dismantling.
Ran into the same problem; Had to use a modelling knife and chip it all away. Used cement glue, as it was the only decent adhesive I had laying around.
Second phone repair I've done - wasn't too terrible. Screws were easier to keep separated compared to the 1.3 and 1.5mm screws from my iPhone 4.
