This is a how-to walkthrough for changing the timing belt on a Subaru EJ255 engine. This is likely the same process for all dual overhead cam Subaru's but the cars that have this specific engine are:
Impreza (WRX): 2006–2013
Forester XT: 2004–2013
Legacy GT: 2005–2012
Outback XT: 2005-2009
Baja XT: 2004 - 2006
SAAB 9-2X: 2006 only