We Miss and Love the Companion Cube

First when you get to the companion cube, in the console, type noclip, then the portal placement cheat (make sure cheat mode is on)

alright get to the chamber lock (don't get in the elevator) and shoot a portal on the wall in there, then go through the wall (not the thing with those dots,or you'll lose your portal) and find your companion cube and shoot the opposite colored portal under it. and take it with you in the elevator