No, you just let the air esape out of the scuba tank, catch it with your mouth (so that your cheeks will balloon), and then blow it into your air tank.
Just kidding ofcourse. Couldn't resist, too easy.
What you need is a fill station. This is a small device that'll screw into the scubatank, and onto which you can 'click' the airsystem at it's fillnipple. That way you can transfer air from scubatank to air system.
Good luck.