BMW: flex disc replacement, bolt and nuts, exhaust muffler

Question
is changing flex disc doable without lowering exhaust system? and do you need to replace old bolt and nuts to new ones?  Car is 87 bmw 325 automatic. thanks

Answer
Genek,
 It would depend on your exhaust system, but you will probably have to drop the rear of the exhaust.  I dont think you will have ot unbold the whole exhaust, but you need enough room to drop the front of the driveshaft.  Usually there are several heat shields between the exhaust and driveshaft, so You will probably have to drop the rear of the exhaust (muffler) so you can remove these shields.  After that is done, remove the 6 bolts in the flex disc (aka Guibo) and then change it.  
 Unless you have bent bolts, I would not worry about replacing them.  They are subjected to lateral forces, and hardly any strain is put on the threads.  Like I said, if you notice any cracking, or bends in the bolts, then I would replace them, but otherwise they will be fine.  
 Hope this helps,
 Josh