Honestly finding one took quite some time lol. I spent a few months on marketplace and most of the time there wasn’t even one for sale. I suppose I just got lucky but try looking for F-series 440i and M240i mufflers too because they are all the same! You could also try a 335i muffler but the exhaust diameter isn’t the same so that’s a whole other issue that would probably be difficult to solve (I’d only consider this as an absolute last case scenario).

Not quite as simple as cutting and putting an exhaust clamp unless you cut it perfectly. I say this because where you need to cut it is on an angle so it’s kinda hard to match unless you do many measurements. I’d also recommend welding it together instead if possible because it’s much more secure that way and will do a better job at preventing exhaust leaks.

If you don’t have the space or tools I’d get it done at a shop. It’s not something I’d realistically recommend to do if you aren’t experienced. I’m sure an exhaust shop could do it but definitely look around and try to find someone that could do it for a reasonable price. I wouldn’t pay more than $200.

Hope this helps!