WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Installing Electromagnet With Torque Specifications
Courtesy of VOLVO CARS OF NORTH AMERICA.
Install a new electromagnet (note the guide pin) and install bolts or new lock ring (diesel) with the bevelled side up.