Don't know how to make backup folder writable

Hi,

I want to backup my site and keep getting this message:

Your backup folder is NOT writable
To correct this issue, make the folder /home/theblog7/public_html/wp-content/backup-db writable.
Your backup folder MIGHT be visible to the public
To correct this issue, move the file from /home/theblog7/public_html/wp-content/plugins/wp-dbmanager/htaccess.txt to /home/theblog7/public_html/wp-content/backup-db/.htaccess
To correct this issue, move the file from /home/theblog7/public_html/wp-content/plugins/wp-dbmanager/index.php to /home/theblog7/public_html/wp-content/backup-db/index.php

I’m not sure where to start. How do I find those files and move them?

Thank you!