Things You'll Need
Instructions
Grip the UMD case by the edges and wedge your fingernail between the two halves and pry them apart.
Remove the disc from the UMD case taking care not to touch the data-side of the disc. If you do, wipe the disc clean with the lint-free cloth. Set the disc aside.
Pull apart the replacement UMD case and place the disc in it with the data side facing the windowed half. Press the two halves of the case back together until they snap in place.