Hopefully this image will help clarify things for 2002-2004 WRX owners. This is a JDM ver7 evap purge solenoid with the OEM JDM hoses attached. It is different on 2.5L models.
Simply mimic this image and then cap off the 2 unused ports (turbo inlet, intake manifold) and you are done. The image on post #1 does not depict it this way, so I'm not sure if that is a mistake in the OE manual.