Steps:1. Mark the panels you wish to replace before removing door so you don't accidentally remove the wrong ones.
2. Take the doors down by removing the hinge pins using a hammer and screwdriver to drive the pin up and out (figure A).
3. Lay the door out on a workbench and sawhorses and run a fine-toothed jigsaw through the louvers (figure B). Dont forget to wear your safety glasses and dust mask.
4. Pull all the louvers out of their slots.
5. Lay the Plexiglas® sheet over the opening and mark the size of the opening (figure C). Mark the plastic so it will fit into the existing grooves after cutting. Mark several points and connect them using a straight edge.
6. Cut Plexiglas® as close to the line as possible with the jigsaw using a fine-toothed blade (figure D). Keep the saw moving at a moderate pace. Too slow and the plastic might splinter, go too fast and it might heat up and warp.
7. Clean up the rough edges of the cut with a file or rasp.
8. Test the fit. If it fits snugly, go ahead and cut trim pieces to hold the panel in the door. Clamp trim pieces into place and mark 45-degree angles at each corner with a combination square (figure E).
9. Cut trim pieces with the jigsaw and file ends smooth. Lay pieces into place and test fit.