I've had to remove the backbox on all my games to get them through my stairways. Pinbot I had removed the backbox several times. Document and photograph all of your wiring harness and board attachments first. It helps if you can take the time to label all of the plugs with wire labels or even painters tape. Disconnect all wires and push them through the hole in the backbox floor, remember some harness plugs may be down in the cab, and you'll also need to remove the braided safety ground that attaches with a wing nut to the backbox floor. Next, remove the two bolts securing the backbox floor to the cab, and fold that down (place a towel down and SLOWLY fold the backbox down). Next, remove the four nuts holding the hinges on - two per hinge - and slide the backbox forward to clear the hinge. Attach the nuts loosely to the backbox bolts so you don't lose them. Reverse the whole process after moving the game.