Need Help With Terrain

I'm making the next map in my series "Day of Defeat", and I am wondering how to make it so you can add another cliff tile. I need to add the Square Tiles cliff to my new Donner map i'm working on so I can make buildings. I looked through WEU but I couldn't find a way. If it's in there or there is another way the help would be greatly appreciated.

Open up WE, and go to
Avanced --> Modify Tileset

You might have to remove current tiles to move others in. It tells you how many spaces you have left. The numbers show how much space each tile will take up, and Red means it cannot be added/removed (green means it is OK).

Hope I helped!

Of course, this is in normal WE, i have never used WEU, so it might be different?

I meant the cliff tiles, the red ones. Is it possible to use the red ones?

You are unable to use the red ones if you didn't start with them. That is what the red means :P And there is no way around it. Maybe there is, but i never knew there was?

You can use WEU enchancer to add up to 16 tiles (or unlimited, not sure) and it can add cliff tiles too.

I surpose you could somehow confuse the editor to give you 500 free tiles, which is all you need for them all.
Iv seen a few maps with 20+ tiles.