If you only need to do the air can seals, it is a fairly easy DIY project. Lots of info on youtube to guide you thru it. If your shock needs more than just air seals, it can be done at home, but it is more involved.
Seals and oil is pretty simple. Just need a few basic tools, but if you’re not confident in it, or don’t have the tools then I’d suggest sending it to a shop.