If you take some tin snips with you you can cut out the rear panel inside and remove e erything very easily, but if he won't let you do that take a long screwdriver, a hammer and a selection of tors bits for the lock. It all dismanltes fairly easily but there is a locking ring on the lock inside that you have knock around to undo. It might also be worth taking some pliers and cutters along with you as there will be a double cable for the key/solinoid that will be clipped into place and there are a few little nuts and bolts which may need to be removed also