Use a plastic opening tool to pry the edge of the home button ribbon cable up from the display assembly.

Start under the contact points on the right and work to the left.

Starting from the left and going right may rip your ribbon cable. The contacts are well adhered to the front panel and should be peeled up first.

If you have trouble sliding the plastic opening tool under the contact points, flip the tool over and gently push against the right side of the contact cable to loosen the adhesive, then try again.