Hello ziggy75,
I gathered what ever tools that I had on hand to work for the various cutting jobs. Straight drills, step drills, hacksaw blades, reamers, flat and round files, sandpaper. Try to protect the surrounding areas with masking tape. Suggest wearing dust mask, rubber gloves, safety glasses and use a vacuum cleaner to keep the mess down to see what you're doing. I think that you could use the rotozip to rough out areas and finish with the hand tools to not make any cutting mistakes. Do some practice cuts and don't rush. Think of the job as sculpting and fine tuning your car and feeling good about the outcome. Harry