To rename files in Ubnutu it is very easy. Use the command for the desired filename name to be renamed.
mv desktop-login.ogg desktop-009.ogg
“mv” as in “move”, there’s no renaming tool as moving file has the same effect. Execute in the same directory where the files are, or use full paths:
mv /path/to/desktop-login.ogg /path/to/desktop-009.ogg