There have been various threads about this.
It's quite easy: just use GCFScape to unpack the models and textures. Then pack them again into your portal 2 map with packrat.
Since this question has been asked quite a lot before and the instructions are quite easy to find I'll lock this thread.
There have been various threads about this.
It's quite easy: just use GCFScape to unpack the models and textures. Then pack them again into your portal 2 map with packrat.
Since this question has been asked quite a lot before and the instructions are quite easy to find I'll lock this thread.