Reference documents:
http://www.yizu.org/archives/721/
The original model is really simple to use Hilink
1, to install some packages:
opkg install kmod-usb-net-rndis kmod-usb-net kmod-usb2 usb-modeswitch kmod-usb-net-cdc-ether
2, add WAN port
3, remember to change it WAN port firewall zone
4, and then on OK