Check out the Volvo Cars web site (US). You would need the diagnostic tool to connect a computer to the car. I don't know what that costs - $1500 maybe? It's my understanding that a subscription can be purchased for three days at a time, at a cost of $105 each time. Assuming you have a suitable computer and a high speed connection, you would probably spend a couple thousand by the time you get anything done. And this doesn't factor in the training that Volvo techs would have.

As I've suggested before, it's viable for the shop that services a minimum of a couple of hundred '99 or newer Volvos per year (think $50 a pop for diagnostics), but otherwise it's probably cheaper to tow the car over to a Volvo dealer for diagnostics and software.

You can buy a bootleg CD or DVD on eBay - some guy in the UK claims to have hacked the code to bypass the subscription time limit. What this would get you is the service manual that Volvo refuses to sell in paper form at a reasonable cost, e.g. $150 like Honda does.