probably a little late but an easy way i’ve found is marking the outlets, make sure the electrical box is flush with the sheetrock and drill 2, 2in. coreholes in the splash so all you have to do is pull the plug through and get screws long enough to get to the holes in the box. you have to clean the middle of the hole out and make damn sure the splash is properly supported, like flat on a clean straight 2×12 pc of wood. lots of stress to the piece while drilling so proper support is key, but in 12 yrs i’ve had more splashes crack from cutting than from drilling