dont need plugin...used grok to simplify....go to luci, network, devices, br-lan, remove lan port u want to use for WAN. Click back to interfaces tab, look for WAN, edit....most important step (at least for me) make note of the current MAC address of eht1 in there. change device to lan u removed from br-lan save. go back to devices, edit lan u removed from br-lan and change mac address to one that eth1 had....for me, it was only the last character that changed