When I hired a plumber the things he did were basically impossible for me. He didn't sweat copper. The first thing he did was heat up the old pipe so that he could screw it out and replace it and by old pipe I mean the plumbing inside the wall, the pipe you'd screw your angle valve onto. I'm not going to play around with fire and screw things up for good. This was actually a freebie and wasn't strictly necessary. Second he connected the toilet which was moved by around 15cm to the right and he used crimped copper, selected parts out of a box with every possible piece you could need and it aligned perfectly. If I had to do that then it would take me multiple attempts and thrown out parts involving multiple trips to the store. I'd also be stuck with tools I'd never need again. Instead the plumber finished the work in around an hour.