http://wordpress.org/support/topic/twenty-thirteen-footer-question

SEE: the comment by OGC Member.  He explains how to modify the code in the footer.php file located in the Themes – Twenty Thirteen directory.  Only the second line of his example code needs to be inserted and customized.  Remember to backup the original footer.php file before you make your edits.  I recommend that you install and use the app ‘Notepad++’ as your php files editor.  Windows notepad is rather inadequate.

Example:  You can add your owe copyright notice to replace the phrase Proudly Powered by WordPress.

See: html Codes Characters and Symbols

Login to remote Ubuntu install through App ‘Putty’ using ssh using and login with the ‘root’ administrative user.

You can copy the content of a folder /source to another existing folder /dest with the command

cp -a /source/. /dest/
The -a option is an improved recursive option, that preserve all file attributes, and also preserve symlinks.

The . at end of the source path is a specific cp syntax that allow to copy all files and folders, included hidden ones.

If you first need to make a new target directory/folder, then you can use the mkdir command, like this:

mkdir /home/yourusername/newtargetdir

All this is useful if you want to re-install a MySQL server that won’t start, and making backups lessen the risk of loss of database files.

MySQL database files are stored in /var/lib/mysql.  This folder ‘should’ remain untouched when you remove or re-install the MySQL package.

It is also a good idea to make a backup of those database files.  I did so using the copy command above.