footer problem

I’m having trouble in placing a footer to my downloaded wordpress themes from themelab.com. Can anyone help me to add some footer to my themes. My friend themes in the widget section it is very easy to put a footer because its already in there but for this theme from themelab.com is not indicated in there.

This is the link of the themes from themelab.com

https://www.themelab.com/2010/02/16/rs17-free-wordpress-theme/

hope you could help me to add a footer like this (4 column footers)

https://img834.imageshack.us/img834/7650/needfooter.jpg

could any one teach me to how to add footer to this templates? Step by step please. I’m not that techy ..