tastes are different and thats fine, so i you wanna go back:
All textures are in the pak files,
if you wanna modify them, you will have to unpak and edit them.
If you want to
override them,
go to your install directory (e.g. C:\games\Sid Meier's Civilization 4\Beyond the Sword)
\Mods\Fall from Heaven 2 030\Assets\Art\terrain\textures\
and then put all files you want to replace into it. thats it. (if the directory does not exist, create it!)
If you need to replace the trees, go to
your install directory (e.g. C:\games\Sid Meier's Civilization 4\Beyond the Sword)
\Mods\Fall from Heaven 2 030\Assets\Art\shared\
I still think those textures are far more fitting and I am aware of the fact, that you have to get used to them until you see every game relevant stuff as fast as you did with the old graphics you were used to. Nevertheless I think its only a matter of short time.
I fixed some stuff:

sorry for causing some inconveniencies for those who dislike them
