Grab and remove the back cover.

If your cover is still sticking to the frame, slide an opening pick around the perimeter until the cover completely separates.

During reassembly:

This is a good point to power on your phone and test all functions before sealing it up. Be sure to power your phone back down completely before you continue working.

Remove any adhesive chunks with a pair of tweezers or your fingers. Apply heat if you're having trouble separating the adhesive.

To apply new adhesive, follow this guide.