The trim pice is captured in place by the wiper arms and also held in place by 6 push pin clips, as well as two corner trim pieces that cover the edges where the a-pillars / windshield meet the fenders. Technically the order of what is removed when does not matter, this is just what I found to be a convenient order.
Step 1: Removal of wiper arms
The fastener that holds the wiper arms to the wiper assembly is covered by a small plastic piece. This can be pried off using a small flat head screw driver.
This will allow access to the nut of the wiper arm. It’s a 15mm one. Regular anti-clockwise removal. A puller may be needed as the arms can be very hard to remove.
It is advisable to mark the location of the wiper arms on the windshield by means of some tape to make it easier to align then when reinstalling.
Counterholding the arm, to avoid putting strain in the wiper assembly when removing the arm, may also be a good thing to do.
Step 2: Removal of side trim pieces
The trim pieces near the edges, next to the bonnet hinge are just clipped in. Getting them into position on the fenders can be fiddly, but they can be half removed. Pulling straight up on the part clipped into the cowl will release them. As they are flexible they can be moved out of the way and can stay connected to the fender.
Doing it now is easier because the wiper arm on the drivers side is out of the way but also the cowl is still holding firmly enough to not move.
Step 3: Removal of misc. pieces
I would recommend removing the cowl seal and battery box covers. The seal just pulls off, it’s just wedged into position.
Front half of the battery box has clips on all three visible sides, carefully (!) pry these away from the catches and release the cover. Rear cover has a locking mechanism that needs a 1/4 turn with a screw driver.
Step 4: Removal of push pins
There are 6 push pins in total. Two on each side near the fender and two in the engine bay.
Pulling up on the stem part will allow the entire clip to come free. These may take considerable force to remove.
On the attached picture the approx locations are marked by a red arrow:
Image Source: Volvo Car Corporation – Volvo XC70 press picture
Step 5: Removal of cowl
Tilting up the cowl slightly and pulling it towards the front of the vehicle will release is from the lower seal of the windshield.
Care must be taken not to get it caught up on the stems of the wiper assembly.
Reinstallation is the reverse of the removal.
Additional care must be taken that the rubber covers around the stems of the wiper assembly sit flat. Otherwise dirt and debris will end up getting in there.