Due to the number of mods for Fallout 3 and New Vegas, we cannot help troubleshoot individual mods. That should be taken to the mod authors website, or a large mod site, like the Fallout 3/New Vegas Nexus.
We can however, tell you how to install/uninstall mods in general, granted them not having a complicated install.
It is simple as dropping all files and folders into the data folder in the game file. Having Fallout/New Vegas Mod Manager will keep your mods tidy, with load order and archive invalidation, so new textures can work properly.
If you need help with the GECK, there is a GECK wikia and tutorial site here.