Yes and no.  It has been done before by frugal home wrenching
enthusiasts, but in general the repair entails replacing the entire
driveshaft which is rather pricey.  Then the trick is to make sure you
get one that has been properly balanced.

Once upon a time drive shafts were common but with the advent of FWD they became
rather scarce unless you had a Merc or BMW or something rather larger like RR or
Bentley. However in the wild lands of the Antipodes there are a few rather large
engined cars carrying V8 engines that are still RWD so must have "PROPSHAFTS"
that require servicing occasionally.

get the drift?

Get the Yellow Pages and look for "Car & Commercial" or Google it.  Any decent
machine shop worth their salt that specialize in propshafts should be able to
re-condition it for you.

Over here in the UK some time ago a few of these companies were offering to
machine our the stake deformations and machine internal circlip grooves to
accept the stock Hardy-Spicer UJ kits.  No need to re balance next time.

When I built my first racer I took my propshaft to the HS factory in Birmingham
to make a complete new one for me. Time 6 hours from start to finish 2 piece
shaft + centre bearing and carrier. Price ----- can't remember it was 1968????

Sir Hugh of Bognor

The difference between men and boys is the price of their toys.

Intelligence is not knowing the answer but knowing where and how to find it!

Hugh Gundersen
hsg@h-gee.co.uk
Bognor Regis, W.Sussex, England, UK

I don't know your driveshaft in particular, but in general I've NEVER seen a
driveshaft that could not have the universal joints be replaced. I've seen
lots of driveshafts, and all of them that I can remember allow the
replacement of the joints. If your application demands the shaft be
replaced, then it's news to me.

On my '94 3 Series cars, the universal joints can be replaced. There is also
a flex-disc in the middle that can be replaced.

Tthere are some points that one must consider if they are going to tackle
this job at home. If you plan on giving this a go, let us know and I (we)
can give you some pointers. I'd give you the pointers here, but it looks to
me like you'll be visiting a mechanic so the tips would not help you.

I think your first order of business should be to determine if you really
need this work done.
 Were there noises or other symptoms that caused you to take the car in for
service??
As far as I know bad U-joints always let you know when they are failing.
One symptom is a noticeable "clank" sound whenever the torque on the
driveshaft is reversed.  This sound should have a ring to it as though you
had struck the driveshaft with a wrench.  The other symptom of bad U-joints
is a noticeable vibration at speeds above 30 mph.  This vibration is caused
by the driveshaft getting out of balance because of U-joint freeplay.  If
you don't have either of these symptoms, I would just keep driving the car
until real symptoms emerged. Then you can take your time deciding how to
proceed.

It is very pricey to buy a replacement driveshaft from BMW so shops have
learned how to rebuild them.
I see the RealOEM price is listed as $675 US.
http://www.realoem.com/bmw/showparts.do?model=1113&mospid=47309&btnr=26_0004&hg=
26&fg=05
 This seems pretty low to me as I recall a $950 quote from my BMW dealer 8
years ago.  If you decide you need to have the driveshaft serviced, try to
use a shop with a good reputation for doing this kind of work.  See if
there's a local BMW club that may have some advice for you.

A good driveline shop can replace the joint itself and ensure that
the shaft is balanced. Around here, this is a fairly easy task, I do
not know of the availability of these shops where you live. BMW will
not replace just the joint and will happily sell you (and install) the
entire shaft. I can't imagine the cost but I'm sure you'd be getting
the shaft twice :)