Very easy. Just make sure to buy a new clamp for the engine side and a new sealing ring for the other end of the pipe and you'll be all set. I'd check the whole length of the exhaust for pinholes though, I thought I'd only need the front pipe and I ended up replacing the whole thing because of rust-holes that were hidden.

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83 M-B 300D- daily driver
83 240D gray market
2002 VW Jetta TDI- beater