i have installed 2 of the files from the 2k textures page, but the other 2 are asking me to overwrite files form mods like COT, pure waters and enhanced night sky, is 2k textures compatible with these mods if i chose to not overwrite any file but still install the 2k texture file, or should i be overwriteing all the files to install 2k textures with no problems, also what happens when i overwrite these files from the other mods?, sorry for the long question still new to modding any help will be appreciated.

The best thing to do when using large texture packs like 2k textures is to to install it first, and then install your smaller, specific texture replacers over the top. Its ok to overwrite the 2k textures with those from other packs you might like.

All that will happen is that one file will overwrite the other, and the texture will look different.

It's really your choice - you can only have one texture replacer of the same filename at once! For example, if you want the night sky texture from Enhanced Night Sky then say "no" when it asks you to overwrite and you'll keep the Enhanced Night Sky texture - or if you want the night sky texture from SkyrimHD 2K, then allow it to overwrite when prompted.

If you're using NMM to install, you can always change your mind later and uninstall both mods and reinstall them choosing the opposite of what you chose before when I asked you to overwrite.

You can also use a mod manager like WryeBash which shows you exactly which files from which mods are conflicting with each other. It will also allow you to change the load order easily without uninstalling and reinstalling.

You may want to use Wryre to install your mods. That way you can easily install and unistall mods.