Super easy, cut out the design on the x-carve.
I then mixed up just enough Milliput and crammed it into the "KEYS" until it was pushed into the entire face.
About 12 hours later I sanded off the excess and was left with really crisp lines.
Estimated time: 10 minutes
I used six 3/4" ceramic magnets I picked up from Home Depot for a few bucks.
Using a forstner bit on my drill press I drilled down enough so the magnets would sit flush with the bottom of the face.
Super glue or epoxy the magnets into place.
Estimated time: 5 minutes