I just replace this hose on a 2006 S60, apparently Volvo switch over to a none vulcanize hose to save money and they are splitting open.

It is very easy to replace, take a long skinny screw driver where the hose slides into the breather box and just twist the old clamp. When you slide the new hose you can actually guide it by inserting you hand under the intake manifold. I started from driver side and just run my hand under the intake until I got the hose inserted in the box. I added a small clamp and was able to tighten it with the same screw driver. This particular car was also missing about 1/2 quart of oil every 10 days. The car only has about 70K on it.