This works for v1.2 of the mod.
Extract the "Skyrim HD" textures folder on your desktop.
-REMOVE *ALL* the .dds files (not the ones inside the subfolders like dirtcliffs, mountains, roads etc).
*Removing those files will fully remove the landscape textures added by Skyrim HD, which are imho not good as vanilla on the med-long distance.
-Now put the textures folder in your Data folder, and overwrite.