WARNING: This page is about a different car, the 2004 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
EXCEPT STI MODEL
Fig 1: Identifying Bulb Replacement Points
Courtesy of SUBARU OF AMERICA, INC.
STI MODEL
Replace the meter main assembly of STI model if it does not function properly, because the warning light and indicator light are made from LED.