To fix lifting paint, I use super glue to adhere the paint back onto the glass.
15 second liquid loctite super glue. 5 second is too fast. Gel is too thick. Longer set time allows the glue to seep into where it needs to go, and allows a few seconds of positioning and pressing.
For pressing, down, just use plastic wrap and let it sit for 24 hours. After that, the plastic will come right off. Just prep the plastic before you start gluing, so you can grab it quickly.