Enabling Multi-Arch in Debian 7.3 [SOLVED]

RSims

I've looked at the guides and I simply don't understand what to do. I recently switched to Debian from Ubuntu for more stability and now I am in the process of changing debian to fit the parts of ubuntu that I liked however until I get this multi arch thing figured out I'm not able to do that.

Was hoping for a step by step on how to do this, which I wasn't able to get out of the wiki. Thanks for the help!

SOLUTION: in the terminal run: sudo dpkg --add-architecture i386 then sudo apt-get update