Washer will spin but not agitate

Washer will spin with no problems, but it will not agitate. You can here the moter running but nothing is moving. Is this the transmission?

hotpoint washer model vbsr2060v1ww,does not agitat but spins out the water,. was told to replace agitator coupling. how do i remove the agitator to get to the coupling. i printed out the exploded view, so far i removed the cap from the agitator. need help