Replacing the power unit: Removal
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.
Remove the blower fan motor and the fan wheel. See Preparations and Replacing blower fan motor
Slacken off the 2 screws in the power unit.