I took my wife's '07 S60 2.5T in for routine service at 67.5K, and was told that the PCV Hose was broken.
The dealer quoted $1700 parts and labor. Ouch.

I found the genuine Volvo PCV Hose (8692217) online at Voluparts Online Store ($26.80). You need 2 1" hose clamps to replace the (ugh!) crimp connectors.

I didn't know if I'd be able to do this repair. A good sign you can do it yourself is if you already have a set of Torx socket wrench tips, 10" hemostats (or long jaw pliers), and a patient can-do attitude.

If you look down at the bottom end of the PCV Hose (you'll need a flashlight, it's down about 6" below the intake manifold, viewable in space between intake pipes), can you see the crimp bulge on the hose clamp?
If you can touch this "omega"-shaped bulge with a long, skinny screwdriver, you have a chance to pull off this repair without removing the intake manifold.

Here's the approach I took:
1. Remove the fuel injection cover and spark plug cover (black plastic panels).
2. Unplug the fuel injection harness closest to upper end of the PCV Hose, and tape it out of the way.
3. Use removal of the hose's upper crimp clamp as a rehearsal for how you are going to have to remove the clamp down below. You're a surgeon. Observe how you will be able to address the lower clamp, given that you're going to have to work through a small portal from above, and also with a long screwdriver from the right end of the intake manifold.
4. You blast open the crimp clamp by inserting a screwdriver tip where the barbs are, between the inner and outer bands. Tap the screwdriver with a hammer to liberate the outer band from the barb.
5. Once the clamp is busted open, use a prying screwdriver from the side, in combination with hemostats pulling upward on the hose remnant to reveal the brass hose bib.
6. Repeat this process to remove the south end of the old hose. Be careful not to puncture the PCV box with the screwdriver. You'll need a utility light lowered down at the right end of the intake manifold to do this surgery. Clean the old barb.

Install south end of hose.
1. Mount the hose clamp tight enough so as to not fall off when pushed with a screwdriver tip, but no tighter.
2. Orient the hose clamp so that you'll be able to tighten it from the right side.
Lube the inside of hose with vaginal lubricant.
3. Stuff the tube onto the lower barb. Before tightening clamp, make sure the north end of the tube is coming up through the proper opening (close to the oil filler cap), and reaches the upper barb.
4. Connect the north end of the hose. Don't forget to plug the fuel injector back in!!

A note of caution...this worked for me. It took about an hour. I think I was lucky in regards to being able to blast apart the lower crimp clamp, and using the upper clamp as practice for dealing with the lower clamp -- that strategy made a difference.