Viktoria

I used 7-Zip to make the folders take less space on my external hard drive but something went wrong - now they are xep-files and can't be opened. I can't access the stuff in my folders which I could before I used 7-Zip. I have tried so many things and is about to give up to solve this problem. Just want to delete them right now and get rid of them. Do anyone know what to do?!!