without pictures and or owning the board i can only tell you to simply screw the antenas into the back of the board.
If it comes with a stand I would suggest testing signal strength with the stand for example on top of the case (depending on your access point's position) compared to just the back. They can sometimes improve sometimes worsen your reception.
The connections shoudl be carefully aligned and screwed in hand tight. They are usually rotatable but be careful as they might not.