Step 4: Cutting the Back Panel
NOTE: **ReInstall the Controller Ports prior to positioning the motherboard or you may not have room for the port afterwards.
Once you find the farthest corner the Motherboard fits, mark where some of the connections on the plastic backing. Then use the motherboard's metal faceplate to identify the exact location you will need to cut to install the plate cleanly. Draw in the area to cut out of the bottom of the NES case, take your dremel and cut away. Then you can install the face place in the lower half and use that as your guide to finish the top half of the case. Check occassionally that everything fits properly (the power button assembly will not fit if its still installed).
Once you finally get it to fit, shaving off edges, filing down corners, etc... then congratulations. Install the motherboard into the back of the bottom of the NES case, and mark the edges of the plexi inside the case so you could place it without the motherboard on the plexi. And yes, you guessed it, take the motherboard off the plexi and set it aside, being careful of that static electricity again.
Lay down the glass and drill 2 more holes through the glass at the edges of the NES expansion port. This will provide us a way to anchor the board to the case with a zip-tie, and allow us to remove the board and plexi without the bolts again. Once drilled, run your zip tie through the case and plexi and back around the bottom loosely. It has to be loosely because you still have to mount the motherboard to the plexi AFTER the zip-tie is installed. If it is tight, good luck getting that motherboard secure. But, but once the board is secure on the plexi, fasten that zip-tie and your motherboard should be securely fastened to your case.