Kumma

So I decided to start mapping some zombie survival maps. I have been mapping before but I have only made surf maps for CS:S.
Now to the actual problem. I need some props from CS:S, but my hammer only shows props of HL2 and some props that I have downloaded from another gmod servers. I tried to google this problem and got solution to install GCFScape. Only problem is that I dont have any clue how to use it.
I know this forum has some great mappers so I would like some help fast as possible.

Here is a screenie of my upcoming map . I still have lot to do.

Yeah , i think the metal makes a perfect mood for the map.