I just spent $32.00 for a 19mm long arm allen wrench to remove the front wheel, I must have been dreaming when I thought there might be a tool in the kit to take a wheel off.
Maybe a bit late for you but hopefully good for somebody seeing it, but I found a spark plug socket at Sears, 5/8", the hex top is (ta-da!) 19mm. And. . . the drive hole is square all the way through the top end of the socket. Yank the rubbr boot out of it, put a 3" extension through the inside of the socket, and you have a 19mm hex key! 4 bucks for the socket.