Here's a short tutorial on converting a cabinet door to accept a stained glass panel. First remove all the hardware. The door may have a finish already applied. Just be prepared to do some touch up to the finish.
The door is ready for marking where the glass panel will go. Center the panel over the back of the door and mark a line around the perimeter. Allow about an 1/8" for caulking/ glue.
It's better to make the cutout slightly larger rather than smaller.
I use a dremel tool with a diamond saw, but a router will work. If you are good with wood, you could use a very sharp chisel. The whole idea is to remove the center panel without causing too much damage.
Here's my cutout after using the dremel tool. Remember this is the back of the door! Any flaws (mistakes) can be filled and painted later. Just make sure the cutout is large enough to fit the glass panel without binding. You want the panel not to touch the sides of the cutout. It's best if the panel is "cushioned" by the caulk. That way if the door is slammed shut the glass won't break. Be sure to use soft close hinges.
After you complete the cutout around the perimeter, use a sharp chisel to remove the lip holding the center panel. Just a few taps with a hammer on each side will remove the lip.
Here's a picture with the lip removed. Continue to remove the other three sides.
With the lip removed, the center panel is easily removed. Either the panel will fall out or a few light taps with a hammer will remove it.
With the panel removed a little bit of residual would needs to be chisel out so the glass can lay flat.
Just make sure your chisel is sharp and remove the rest of the wood. Don't use too much force or you'll damage the wood frame.
After about 10 minutes of chiseling the job is done.
The wood surface can remain rough as the surface will be primed, painted, and then a thin coat of caulking/ glue will be applied. This provides a cushion for the new glass panel.
The slight gap will be filled with caulking/ glue to provide a cushion for the sides of the glass panel.
Place the panel in the door and make sure everything fits.
Here's the front of the door. Note how flush the glass panel fits in the opening.
I'll remove the glass panel and prime/ paint the door. The door will then be ready to mount the glass panel. This concludes the short tutorial on converting a cabinet door. Stay tuned for the finished cabinet door installation.