Hello tbieling,
When it comes to removing any battery, you obviously need to be careful. Any puncture, ''severe'' bend, or damage can cause it to smoke and or catch fire. First off, if this is your first repair, I would recommend doing this in a garage or near somewhere outside therefore if something does go wrong, you will not be near anything flammable. I have replaced many iPhone batteries myself and some are really stuck on. I can get away using a cheap method that forces the battery out and tears the adhesive, but it is not the same on the MacBooks. It really just comes down to being careful. You can get adhesive remover which if you use enough, may make it as simple as prying, but I doubt you will have enough to do that because they are kept in place almost water tight against the frame. Sadly, the MacBook does not have adhesive strips like the iPhone, so all you can really do is use adhesive remover and heat. I would recommend just following the iFixit guide and you should be fine. Some adhesive remover, heat, and gentle prying and you should be fine. :)
If you do have any issues, reach out or comment and I will be happy to continue assisting your situation. I like it when people try and fix their devices. I started just like you, and here I am. I still have issues, but the experience is the best teaching you can have.
Hope this helps!