Help installing drivers by remote on OS X

Hi folks, I need a bit of help with a major problem I'm having. Recently, a friend of mine had his graphics card crap out on him due to static damage. He's chosen to replace it with an ATI Radeon 4870, a card which several local Mac techs have assured us will work.

Now, the issue with the old card is that it "kind of" works, in that we can use the desktop for about 10 minutes before it shorts out again. Animating anything (like opening a window) will also do this. With that in mind, we have a problem.

To my knowledge, the 4870 needs some configuration done, not the least of which is installing new drivers. Sadly, he doesn't have Snow Leopard, just Leopard, so the driver isn't onboard (my understanding is that Snow Leopard includes the driver).

How would I go about installing this driver? I have a Macbook Pro on hand, I have all the wireless and wired internet in the world to work with. What can I do to fix this?

Thanks for all your time!

 

Well, I really do appreciate everything thus far, but before I've even been able to try any of it out, it seems we *may* have another problem entirely. Is there a discrepency between a "Mac" 4870 and a "Windows" 4870? Are these in fact different cards somehow, or is someone pulling my leg?

My friend just went down to a computer place to purchase an extra power cord, and the tech told him that apparently he has the wrong version of the 4870, and that it'll never work in his Mac Pro.

That said, if that's the case, we have a bit of a problem. My question from there is where the heck we can find a graphics card without breaking the bank. He had an 8800 GeForce in his Pro before the card gave up the ghost, and because he's a digital artist, he does need something comparable. Is there anywhere you guys know of to get comparable cards without shelling out $400+?

Thanks!