Volvo Repair: changing belt, crank pulley, volvo s 80

Question
99 volvo S 80  2.9l
1. how do you change the drive belt.
2. when should you change spark plugs and change transmission oil

Answer
Scotty, there is no service for the Transmission on the S80.  The drive belt is a pain in the neck and a long 14mm wrench is needed to collapse the pulley.  You also have to remove the dampner cover on the crank pulley.  Not sure you would want to tackle that one.  Roger