Locate the noise bumper that helps secure the home button flex cable to the frame

Use the Halberd Spudger to gently lift the bumper off the cable and frame

No heat should be necessary. But if you feel safer applying heat, only apply a small amount, as there is only a small amount of adhesive

Be sure NOT to rip the flex cable. This can cause irreparable damage to the home button and cause TOUCH ID to not work