First, the laser cuts at a *very* slight angle, so be sure to put the door back in the way it came.

Next, place the case on its side so that the hinges are at the top.  Place on a nice soft spare towel so you don't scratch the acrylic, but not one with a bunch of lint on it.  

Loosen up the screws for the hinges so they can move easily.

Move the door around slightly so it's in the middle of the hole.  

Use the magnetic for latch to hold the door in place while you tighten up the screws.

Put the enclosure back into position and test the door.