FIP on an m51?
Depends which seals and what’s leaking. Generally you should manage. There’s enough room if you take things off to get in there, you need to scribe everything up and will have fun readjusting modulation if you move the pump top. You need proper tool to hold the sprocket in place if you remove the FIP drop that and your stripping engine right down
Good read of RAVE beforehand so you know what not to touch