It is used exactly the same as all weapon styles, where you can use an outfit station to apply that staff style over whatever staff your character would normally have equip.
I'm sorry to have to disagree NeeScrolls but if you read the blurb, at the place of purchase, it clearly says...(paraphrasing)..." when you put the weapon away, it becomes invisible." Ergo, you can't see the sheath of arrows on her back. But you can see the bow and arrow in her hand. It always pays to read the small print.