A reputable drive line shop could replace them for you (it's definitely not something you could do yourself), but then you also have the center bearing that is a wear item, yoke bushing, lock nut, balancing, etc. and by the time you're through, you're probably spending as much, if not more, than just buying a replacement drive shaft outright, which is why people don't even bother- they just buy the rebuilt shaft. Don't forget to replace the giubo (flex disc) and corresponding nuts/bolts when you do it.
Expect to pay $350-500 for a replacement shaft but once it's done, you're good for another 100K+ miles. __________________ 
1995 318ti Base - Cosmosschwarz/Sandgrau R.I.P.
1997 318ti Active - Alpinweiß III/Sandgrau
2013 328i Coupe - Le Mans Blau |