My washer did not agitate. It would spin and the motor sounded like it was agitating.

I pulled the top of the agitator off (the softener dispenser) then pulled the agitator itself off. I had to pull with some force. I used the socket wrench to remove the bolt on top of the agitator coupling. I then pulled off the old agitator coupling, replaced it with the new part. Used the socket wrench to tighten the new bolt. Lined up the slots on the new coupling with the agitator top, it slid on with a little resistance. The last part to replace was the softener dispencer.