Change Configuration/Change WAN Port

Just opened box and connected RB951Ui-2HnD. I have a Ubiquiti Bullet 2HP High Power Access Point that needs POE to operate. I would like to power it from the Routerboard router, but I need to configure Port 5 (the POE power out port) as the WAN port, and make Port 1 (the POE power in port) just a slave. I will not be connecting anything except the Ubiquiti to the router with ethernet cables (except for maybe configuration) so all I need is to get the signal from the Ubiquiti into the router to be broadcast via wifi.

Given that the router has not had any changes yet, can anyone list the fewest steps to accomplish as described? My knowledge of routers is somewhat limited, so I certainly appreciate any help someone is willing to offer.