I took the glass out of a picture frame and laid the plastic on it. Heated the plastic with a heat gun until it got soft and started to lay flat on its own and then immediately laid the glass from the pin on top of the softened plastic until it cooled (like 15 mins) and they are as flat as a board now. Make a glass-plastic-glass sandwich. Just be careful with the heat and don’t keep it on one spot too long.