How do I change to different terrain tile sets without changeing all the terrain?

[Fallen_Warlord]

How to I change the tile sets of my terrain without changing whats already on the map? For instance, Cityscape - Ashenvale just to put down specific grasses etc for forests.

 

[Losam]

You can try:

> Replace the textures (. BLP) for texture files that consume only one space
> Use textures that consumes only space