What year WRX? The process is about the same, just pulling them apart is different. Basically, throw the headlights into the oven at 200-300 degrees for 15-20 minutes. What you are doing is softening the glue which holds the housing together (it also seals them from moisture). Once its nice and soft, pull the housings apart and take out w/e you want. Make sure you seal them back appropriately to avoid moisture. Let me know if you have any problems.
+1 on buying some silicone to seal the lights back together. I didnt and got a lot of moisture so i had to rebake lights, dry them out, and reseal them with so extra silicone. also, its kinda scary at some parts. dont be afraid to muscle through some parts. when i first did it my friend that was helping me kept telling me to look somewhere else and when i did he would just yank at stuff to get it off/apart. also try scoobymods.com, they have good stuff. good luck.
yeah i used scoobymods.com and Nasioc 's directions....pretty easy....make sure you leave it in long enough to soften the sealant......i was squimish about that and my first light took me like an hour and a half because i never got it hot enough...that's my only advice....