CAREFULLY
First remove the small rear end cap pieces then...
Start the the base of the windshield and pull straight up one clip area at a time, be careful not to bend the molding.
Pull with primarily your left hand, stabilize the molding with your right hand (reverse on the passenger side)
There are several clips, you may break some of them so you should buy some before you do this so you can put it back before waiting to buy new clips

 

Are you installing roof rails?

 

Probably not LOL , maybe a replacement. I had to do that on my 04, as the trims started bubbling from aluminum oxidation.
http://forums.swedespeed.com/showthread.php?133940-Front-Windshield-Trim-Rust

 

I just did this on my 04, but I have roof rails so my number 20 is shorter than yours. I replaced my, what volvo calls Drip Molding, because the rubber gasket on the side had dired out and was brittle, crumbling away. It looked bad.

It tooks months but I finally found someone parting out a P2 chassis with the same black color whose moldings were in good condition. I could have bought new, but they're over $100 each. I also bought a whole bunch of yellow clips from iPd that you'll need to reattach. Some people say you can reuse your existing clips, but I didn't want to risk it, they are not designed for repeated usage.

To remove, grab the bottom and firmly pull up. The moldings themselves are quite flexible and you'll find the yellow snaps will break away before the moldings are damaged. On my 04 there were 3 yellow and 1 white clips per side on the windshield area. I didn't buy replacement white clips as iPD didn't have them, and the yellow ones work fine.

Once the molding is off, remove the clips that are still attached to the small pegs in the A pillar. I used white cutters to get out the pesky white clips. Now, snap your new yellow clips into the channels on the underside of the molding, line up the clips to the pegs, and insert the clips into the pegs. Once firmly seated the clips will be pulled into the side of the pillar, snugging the molding down onto the pillar. It's hard to describe but obvious once you see it for yourself.

The best technique I found for snugging the clips is to use a length of sturdy ribbon. The idea is to put the ribbon in before you snug the clips, either above or below the clips (depends on which side you're doing), then push the molding into place and use the ribbon to pull the clip into place. Once it's snug, the ribbon can be pulled out because it's thin and flexible. Now, move onto the next clip. I did 4 yellow clips per side, then are less than $2 per. The clips come with an arm attached that I think you're supposed to use to snug it into place, but I found the arm worthless and I snapped it off before starting each one. Maybe you'll have more luck.

I just did this 2 days ago, very timely thread!

 

replacing trim moulding on 2005 S60

I got the little windshield corner trims, some extra push downs for those, and the yellow connectors from ipd, and then I ordered just the trim mouldings from volvo dealership with my matching color code for my model. These each came in huge boxes that were about 8' by 1' by 4".

You take off the corner trims on the windshield first, these are rubber and they pull right up. The old ones almost disintegrated on the spot.

Then I worked from the front of the car and gently snapped off the old trim molding strips, working backwards.

The trim easily snapped off of the 3 yellow, the white, and the 7 black connectors. You do not need to remove the luggage rack brackets. The new trim moldings had white connecters already pre-attached, and the black ones were easy to re-use by leaving them on the car. A couple of them came off with the old trim, but these are 2-peice and they easily snapped back onto the car and reset. Have these black ones on the car already when you start.

To install the new trim, first slide the yellow connectors onto the front of the trim, with the little arms outwards. Then starting from the back of the car, connect the trim to the back trim piece. Always hold down the trim with one hand or a second person, towards the back side of the car, so the previous snapped down section does not pop off again.

As you install the trim, the bottom of the rubber gasket should sit right on top and should not be jammed underneath the windshield, etc but rather laying on top of it. This forms a channel for the rain, that runs down to the front of the car below the windshield wipers.

Simply use a fist to tap down the trim on the black clips. Then the two white clips are meant to clip on one time by sliding the trim upwards towards the roof of the car. Simply slide the trim a little forwards or backwards to line it up and then slide it up to clip it.

The yellow clips were the hardest but the little "arms" did work for me most of the time. The trick is to line them up so that the large hole is over the little post, then hold the trim down very firmly, and use the arm to slide the clip over the post. If it does it right you will feel a bit of a ratcheting as it tightens, and then the clip will break right off when it gets tight. You need to keep holding this one down as you do the next one, otherwise they could all easily pop up.

By the time I got to the bottom yellow clip, I had retried enough of them that I used up all my spare yellow clips with arms, so I resorted to some strong ribbon, from the previous suggestion in this thread, and that worked like a charm to finish up.

The new corner trims clip down the end of the trim molding to complete the bond, and now it all looks like new again.