It is a fairly simple process, involving removing the shields at the top, loosening and removing the old belt, putting the new belt on, and replacing the shields. But since you are asking here I would recommend taking it to a professional.
I found no mention of a power steering filter in the owner's manual or in the service manual for Outback.
There is no Power Steering Filter on a 2002 Subaru Legacy/Outback.
The 2009 Subaru Forester is 5 ft. 10.1 in. (70.1 in.)1 one-touch power windows wide.
The 2013 Subaru Forester is 5 ft. 10.1 in. (70.1 in.)1 one-touch power windows wide.
The 2001 Subaru Forester is 5 ft. 8.3 in. (68.3 in.)1 one-touch power windows wide.
The 2014 Subaru Forester is 5 ft. 10.7 in. (70.7 in.)1 one-touch power windows wide.
The 2002 Subaru Forester is 5 ft. 8.3 in. (68.3 in.)1 one-touch power windows wide.
The 2007 Subaru Forester is 5 ft. 8.3 in. (68.3 in.)1 one-touch power windows wide.
The 2004 Subaru Forester is 5 ft. 8.1 in. (68.1 in.)1 one-touch power windows wide.
The 2010 Subaru Forester is 5 ft. 10.1 in. (70.1 in.)1 one-touch power windows wide.
The 2008 Subaru Forester is 5 ft. 8.3 in. (68.3 in.)1 one-touch power windows wide.
The 2003 Subaru Forester is 5 ft. 8.1 in. (68.1 in.)1 one-touch power windows wide.