Maybe this might work for you: Tape the top where the cut will be,
turn it over and make the cut using a carbide blade in a jigsaw, or
even better a diamond blade in a hand circular saw. Clamping a cutting
guide to the piece is a good idea as well. There are online sources
for the blades you need, as well as some stock at Ace Hardware, box
stores, etc. Harbor Freight has a good selection, too, if delivery
time is not critical. HTH
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