Before you install new adhesive strips, remove all of the old adhesive from the perimeter of the rear enclosure.

If you are re-using your existing display, you must also remove the old adhesive from the back of the display.

Peel off the old strips of adhesive using tweezers or your fingers. Start at the bottom and peel upward towards the top of the device.

After all the old adhesive is removed, carefully clean off the adhesive residue with high-concentration isopropyl alcohol (90% or greater) and a lint-free cloth. Wipe in one direction, not back and forth.

Don't skip this step, or your new adhesive strips may not bond properly, and the display may fall out of your iMac.