Im trying to improve inns in my Skyrim. And going to use 3 different mods for this: ETAC, Unique Taverns and Realistic Room Rental. First two are modular, but RRR is all in one. I need only few inns from there, can somebody explain me how to easily delete all others?

you could use TESVEdit

but if they have scripts or references attached to those places/objects, then it might not work out so well.