How to install glass into a a hollow wooden door?

I have 2 old, hollow, wood doors and 2 extra cabinet doors with very nice glass( glass in a wooden frame). I want to take the glass off the cabinet doors and put it on the old doors. How should I proceed?

I am also planning on changing the color of the wood doors.

I guess this would really depend on your woodworking skills. Hollow core doors are just that. They only have a small amount of wood around the outer edges. You would need to cut out the opening for the size of the glass panels, build and insert a frame work to support those panels, anchor them to the outer wood uprights and then frame the panels after installation with molding. It wouldnt be terribly difficult, but if you are not a handy individual or dont have a lot of experience in woodworking, it may be just a little more headache than it is worth. On the other hand, since you already have all the parts, you really have nothing to lose by trying.

Here's how I would do it.

1. Place the door on the floor or on a work bench and place the glass directly on the door in the exact spot you want it to be.

2. Outline the glass to mark the area where you will cut the door and add an additional 1/8" all around for play. Remove the glass and with a Scroll or jigsaw cut the area out. Since the door is hollow, meaning that there is nothing in the middle section except two plywood pieces, it will be flimsy and without support. Now you will need to reinforce it on the inside (between the two panels).

3. Measure the thickness of the door by using the outer edge noting the size of the filler (the wood in-between the two plywood outer sheets, not the plywood) to determine the thickness of wood needed for the inside supports. Once determined, cut the appropriate size and insert the wood pieces between the two outer sheets and glue together. Do this on all of the four insides so that you will have a solid inside frame.

4. Take the thickness of the glass and subtract it from the total thickness of the door, including the outer plywood sheets, not just the filler wood. Now divide this in half and this will be the thickness of the molding which will hold the glass in place on the inside frame of the opening. Measure and cut the inside molding and with tack nails install one side of the molding first. Lay the door flat with the installed molding on the bottom side and slip the glass in. Now install the other moulding using tack nails. The glass should now be held by the moulding which should be flush with the outer panels.

5. Finally, you can cut and install outer moulding of your choice aorund the opening edges.

6. Sand, prime, allow to dry, caulk, allow to dry and then paint the door and you are done.