Delete wordpress from server

Hi everyone.

I quite messed up my server and i’d like to delete everything and upload again my website from a clear backup.

I was running multiple websites on subdomains and trying to move one of them to the main domain i fucked up..

I’d like to erase everithing and install one of the websites that i have on a subdomain on the main domain and another one on another host/domain.

could you help me with a nice guide on copying all wp files and the database and putting it back with the needed changes to the files?

Thanks a lot

T