Route Wlan0 traffic trought openvpn

Hello all together

I have the raspberry pi 2 and the Edimax EW-7811Un wireless dongle working on my pi. I followed this toturial http://www.daveconroy.com/turn-your-raspberry-pi-into-a-wifi-hotspot-with-edimax-nano-usb-ew-7811un-rtl8188cus-chipset

Furthermore I have an openvpn client running on my sweet machine and all traffic on the raspberry pi is "hidden" in it. So now i want that all my devices that are in the wifi from the edimax dongle are also "hidden" behind the openvpn. So I tried a little bit with the openvpn interface tun0 and br0, but I didnt get it working. So i need the advice of someone.

Thanks in advance.