Some cats are definitely more difficult than others. What stage in this process are you at? If you are still struggling to even get the harness on, try to spend a few minutes each day just laying it on him, then loosely attach the straps for a few minutes at a time. Once you are able to put it on him snugly, he will undoubtedly roll around and act a bit crazy. It may look disconcerting, but if you continue to do this each day, or a couple of times a day he will eventually get used to it. Once he's used to the harness you can attach a leash and just let him walk around dragging it behind him for awile. Then once he gets used to the leash, you can start trying to pick it up and guide him with it. I find the easiest way to teach them to walk with the leash is to use a wand toy to encourage them to go in the direction I want them to go. Good luck, I hope you are successful!