I've just find a way to change radio key without editing gamedata.pak!
1.Go to your "State of Decay Early Access" folder
2.Then go to "Game" folder
3.Once your inside the "Game" folder create a folder name it to "libs"
4.After you created the "libs" folder make another folder inside the "libs" folder name it to "config"
5.Then download this file: http://www.mediafire.com/downloa ... totypeactionmap.xml
6.After you downloaded the file put it inside the \State of Decay Early Access\Game\libs\config\ folder
7.Then play and have fun
In this .xml file radio will be bound to left alt.