The UNIX command "chown" should do this. Typing "man chown" or "chown --help" will bring up the full documentation or it can be seen here: http://unixhelp.ed.ac.uk/CGI/man-cgi?chown The general syntax to change the owner from root to yourself would be
sudo chown <your username> <filename>
You could optionally give yourself permission to do this. chmod is the command that does this.
chmod a+rwx <filename>
This will give everyone on your system permission to do anything with the file.
see "man chmod" or "chmod --help" for full details