installing a Radeon card in os 8.6

Hey, new to the forums and mostly new to macs as well. I'm mostly interested in retro gaming and recently Ive decide to upgrade a 7600 I have. it currently has a g3 cpu upgrade and os 8.6 but I wanted to add a video card. I was thinking a Radeon 7000 paired with a voodoo 2. I read that the Radeon 7000 can install to os x and 9 via fine but the install for os 8 is a little tricky and I was hoping someone could point me to a guide to do it or tell me how tricky it is. keep in mind as far as macs go my knowledge is pretty basic so when someone says "manually install the extension into the system file" I go "extension??? system file????

OK, well maybe not that bad but not to far off.