Place the 4×4 under the cut pallet and screw the bottom pallet boards to the 4×4 (as shown below). This 4×4 will give it the correct angle for the game.
Turn the “cornhole skeletons” face down onto the plywood. Trace around the body of each of them and then cut along the traced lines with a jig saw. You could also use a circular saw here if you have one.
Measure and mark the side moldings to the length of the sides of the pallet. You could salvage some of the pallets to wrap it, you just might need to sand and patch.
Find the center point of the hole, about 9″ down from the top and centered from sides, then trace around the lid of a standard paint can (or around anything that is 6 inches in diameter) making sure that it is centered to the board.