This is an easy job, done on the car. You need to remove the parking light and the plastic shield below the lens. I've doen it twice, one per side.
Be careful with the old glass (sharp edges) and do not try to clean the mirror, you'll take the very thin silver coating off. A vacuum or a can of Dusf-off is good for cleaning the area. I always reuse the original clips and gaskets, I found the to be of better quality than the ones that came with the new lens (I used third party lenses, Volvo does not sell just the lens)