Android flash question

[Lean L]

I recently got an Android phone and am enjoying the customs roms very much. I have a question about a flash though. Since these roms come out so fast, and I don't want to have to reflash some of my customizations, can I just download the updated firmware, take out the sense UI files and flash over the old one? Would this leave the sense files as they were or would it be replaced by nothingness?