[Plugin: Google Maps v3 Shortcode] How to activate in sidebar

It works for me, so perhaps it’s a theme setting? I did find this article that might help.

https://www.wprecipes.com/how-to-add-shortcodes-in-sidebar-widgets

Trying to do the exact same thing with this plug in. I see the tip about adding the line of code to enable complete sidebar functionality, but where in version 3.1 can i go to edit my theme and put in that piece of code?