The vibration motor's flex cable is very fragile. Work slowly to prevent tearing the cable.

With blunt nose tweezers, grab the base of the flex cable as close to the frame as possible.

Slowly and steadily peel the cable from the frame.

If the cable feels stuck or re-adheres, apply more isopropyl alcohol or heat.

Remove the vibration motor from the frame.

Apply new adhesive to your vibration motor before installing it in the frame.