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 Vacuum Tank
Courtesy of VOLVO CARS OF NORTH AMERICA.
Remove the vacuum tank.
Disconnect the hose to the vacuum tank.
NOTE:
Make a note of how the hose is routed. It should be routed in the same way when it is reinstalled.