WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Air Vent Housing Torx Screws
Courtesy of VOLVO CARS OF NORTH AMERICA.
2 Torx 20 screws for the air vent housing. The air vent housing is located on the reverse of the dashboard.
Remove the damper control from the air vent housing and pull it out.