Well, since you asked... I just did that part to my 100g. Just taped some trash bags at the ends to keep overspray off the side of the tank and shot it. Took one can. Went over it a total of about 4 times and a 5th to hit any spot I could still see light through.
Mind, that looks like a sweet spray job. I wish I had the time to do this when I set up my Tang tank and will do it for sure the next time I rip the tank down. It looks like it was a relatively simple project with huge benefits!