Great for old jobs. Here are a few tricks I've learned. If the box is not in the wall, use a screwdriver to screw the screws in a little, then back them out so the screw tips are flush with the wall. When you cut the hole, make the hole tight enough, even so tight that you have to use a rubber mallet to tap the box. This will help keep the box level. (But not so much that the sides deform.) Before using the impact wrench on the screws, use a screwdriver to drive the screws in as far as possible and then back them out. This provides more clearance before the striking tool "fires" and this limits stripping. For wires and slots, insert a flathead screwdriver into the slots, insert the screwdriver into the slot, and wiggle the screwdriver back and forth. to open the slot. There is also a middle piece of plastic between the two corner pieces that form the slot. take it off