The phrase “can of worms” comes to mind when I think about the DIYer servicing an AC system. There's so much to be considered. Technicians have to be certified to work on AC systems; that should tell you something. But even that's not enough most times. You also need a good amount of experience working on AC systems. With that said, I strongly recommend you take your AC work to a professional. They have the proper equipment and experience to get the job done, or at least they should have it. Weigh your options carefully before you tear into your AC system. AC parts can be expensive; I'd hate to see you install a new expensive part that didn't fix the problem, or end up damaging your system due to improper service. Ignorance can cost you big time here. Proceed with caution.