I was trying to remove the rear quarter interior trim inside of the wagon so I could run an XM radio antenna wire from the tailgate area to the radio. Anyway, I'm stuck, there are these grey plugs, I already busted one trying to pull it out, and I'm wondering if it's just a part you break and replace when you take this part of the car apart, or if there is some trick to getting them out without breaking them. I'll attach a photo so you see what I'm talking about.

http://sparc.fcu.com/~bri0486.JPG

The wholeback half of the car must come out...seats, panels, everything:(

flooring, styrofoam, ... etc. Take it all out - trim comes off last.

Subaru service books are the best source of information and a great investment.

Here are the instuctions for removing everything. I have done it to two wagons for roof rail removeal, and one to install a XM radio.
Should have all the info you need.

http://forums.nasioc.com/forums/showthread.php?s=&threadid=110345&highlight=roof+rails