An inch long crack appeared in the door of my terrarium. Exo Terra doesn't provide replacement doors, does it?

If not, I may need to use aquarium sealant to prevent further cracking. How long should I leave the frogs out of the tank while it cures?

I don't know what caused it, but the crack is on the inside of the tank. There was a heat lamp overhead but the glass didn't seem to be all that warm. I had a friend change the water for me. The bowl's kind of heavy but she says she was careful not to hit the door. Maybe the frogs were heavy enough to break it by throwing themselves at it? Heh.

EDIT: Apparently I can buy a new door but I'm terrified of breaking the plastic hinges while replacing it. Any tips?