First, let me emphasize that you should not attempt to do this unless you know what you are doing. If you make a mistake and mess up the /usr/share/X11/xkb directory you will brick your device and need to reflash. I know because I did. This assumes that you have already enabled HID bluetooth by editing /etc/bluetooth/main.conf as described elsewhere. And that you hae already installed /usr/share/X11/xkb-chinook from the tar file that I posted earlier in this thread.