dual wan rb951ui

Hi all,
We bought this router RB951Ui-2HnD routerboard. It’s small and has 5 ports wherein port 1 is the default WAN port. I new to this router OS and the web GUI is quite overwhelming. However, here is were i get stuck.
I want to make port 1 and port 2 as WAN port, and every time I change something on the web GUI i can no longer access the device as I’m connected to the LAN port.
I’m aware that I should connect using a serial console connection but how? This small router has no console port (or should I open it).