WARNING: This page is about a different car, the 2002 Subaru Outback and 2002 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect ground cable from battery.
Remove lens (A) and spot light mounting screw (B).
Fig 1: Removing Lens & Spot Light Mounting Screw
Courtesy of SUBARU OF AMERICA, INC.
Disconnect harness connectors and remove spot light.