Exit button to shut down Android

Hello,

i am running kodi 16.1 and modified it to run as Launcher on my cs968 Android 4.4.2 TV-Box. Now i am about to do some fine-tuning and want to know, if it is possible to remap the shutdown button on the main screen to shotdown Android.
Right now it is just exiting and restarting Kodi.
If not, is it possible to remove/hide the button?