It's not scary at all. Just buy that tool in post 7. That bottom piece of trim is already trash so just practice on that piece until you get the hang of it. The tool slides in between the seal and the trim. Not the trim and the body. If you break a clip, a new one literally just screws in with a small screw.
I wouldn't mess with a window seal unless you absolutely have to. If it ain't broke, don't fix it. That's especially true with front and rear window seals since it's getting harder and harder to find people that are able to seal them up properly.
