Open the door to the cabinet or enclosure and remove the screws used to secure the hinges to the cabinet. Use a screwdriver or a power drill to remove the screws.
Remove the door and set it on a table or bench. Examine the back of the door for any small nails used to secure the wood panel to the frame. Remove any nails with the pliers.
Create a template to use for cutting the hole for the glass insert. Measure the length and width of the door with the tape measure. Subtract 1-1/2 inches from each measurement and transfer the measurements to a sheet of paper. Make an outline using a pencil and straight edge. Cut out around the inside of the outline with the scissors.
Place the template on the cabinet and trace an outline on the cabinet door with the pencil. Set the door on a pair of saw horses and clamp it in place.
Drill a hole in each corner on the inside of the outline that you drew in step 3. Insert the jigsaw into one of the holes and cut along the outline.
Remove the inner section of the door and then use the router to cut a small ridge along the inside of the door. The ridge is used to set the glass panel in place.
Set the glass panel into the wooden frame. Attach glass clips along the perimeter of the door with the power drill.
Re-attach the door to the cabinet to complete the project.