As a temporary solution, simply do not enable the relevant .esp files in the launcher.
I believe that Steam can be contacted to remove DLC from your account.
You must have at one point chosen to download it; it's considered a (free) DLC.
***
So, will one receive this download if one has the Hi-res pack, or must one also have all relevant DLC?
Well i never used the mods ingame...ever as i mentioned. And even though i can not prove this over the internet...i assure you that i
never hat any interest in the HiRes pack and as such never downloaded it, I realize that sounds weird to say the least i guess, but it is the truth none the less.
But how or who can i contact then at steam to have the HiRes texture pack removed from my account?