Step 1: Here's How You Do It
If your UMD case is cracked or badly damaged, buy a replacement from here.
Note: if the case of the UMD was just split into half go directly to step 4
1.start by slowly opening the broken case, the flathead screwdriver may help.
then get the UMD out and place on a surface that is flat and smooth (NOT THE FLOOR!) printed side down.
2. for ones that the UMD plate at front messed up, just pop it back into it's original position and apply some glue on the edge where the clear plastic meets white plastic. Then put the disk in, close the case and put some glue along the side.Look at photo for description.
3. for ones that got the new case(s). open the new case, put the disk in and pop it close. You may need to apply a small amount of glue around the side to seal it.
4. for ones that case is split in half, close the case and simply apply glue around the side.