First step: Get an electrical contractor to give you a quote for the work that will meet your requirements. If anything touches or goes through common areas that are not under your exclusive control, you must get HOA approval for that portion of the work. If not, you're home free and don't even need to notify the HOA.
True, but I'll need HOA approval for common areas. I'm trying to get new power from the electrical closet that feeds the multi-unit building to my private garage, since I can't do anything with the inadequate 60a 'full' panel in a really inconvenient location.