The way they do it in a dealership is:

1)Turn loose the outer tie rod end and the front stabilizer link rod where it attaches to the lower control arm.
2)Remove the bolt that goes through the bracket that holds the brake lines to the frame. Lift that plate with the lines on it up and position it infront of where you just took the bolt out of. This will allow the caliper and lines enough room to stretch.
3)Shoot loose the three bolts that hold it into the strut tower.
4)With everything loose push down on the assembly and lean it out of the fender well. You may have to push hard right where it comes out of the actual fender well or it will hit/scrape.
5)This is the real answer to your question here, with the strut housing assembly leaned out there is a factory Volvo tool that looks like a double ended hook. One end hooks around the strut housing and the other hooks through the eye of the stabilizer bar where the link rods goes. I doubt you have this tool so you will need to use a few wraps of tie wire or something. Done properly there will be no stress on the brake lines and you can take your time to line up the compressor and remove/install the big body nut that holds the cartridge in the housing.

It takes about 20 minutes per side if you have done a few. Please heed the warnings about that coil spring. I do know a few people that have had them get away from them. The results ranged from "It felt like Mike Tyson hit me in the chest" to one guy that is still undergoing reconstructive surgery on his face and will never ever be the same again. Be careful.

Mark