In this video we attempt to use the heated bed from a Creality Ender 5 Pro 3D printer to help remove the rear glass cover on a Samsung Galaxy S8 smartphone. It ended up taking around 5mins at 80c to heat it up sufficiently to soften the glue.
I would recommend discharging the battery to 0% first to reduce any potential fire risks.
Please note this video is just for information purposes and attempting this yourself is entirely at your own risk!