There is a write up here on how to take the instrument panel out: http://www.volvospeed.com/Dashremove.php
Most people who do this recommend changing all the light bulbs while they are in there as you don't want to take it out often. I have taken the panel out to change the broken gear on my odomenter so I know it can be done without too much of a problem. You'll need the torx screw driver or equivalent tips if you're using a driver with interchangable heads. Read the section and go buy the right ones at most any autoparts store. Doing it yourself will save you a ton of money over the dealer.
--
1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.