We did ours ourself. A 4 1/2" angle grinder, actually I think we burned one out!! Go get a couple lenox masonry diamond wheels at Lowes, cut them out to the size of the new box and morter the new ones in. I have 7 bays we did 3 bays one day, and did the other 4 bays a few days later after we got everything hooked up on the first 3. I have a very handy worker that between the 2 of us we do most everything ourself. Not sure what boxes you got, but just plan ahead for how you will be securing the boxes in place, weld tabs, holes for for lags, or bolting boxes back to back. Take your time and you should be good to go.