The cogs had worn down and would not engage the agitator to agitate the clothes

I pulled the dispenser cap off the top of the agitator, then removed the water tight cap from inside, then used a socket and extension to remove the bolt and the top portion of the agitator. The cogs and holder easily came out of the agitator, then the black hold down ring was slipped away from the cogs and the cogs then easily were removed and replace with the new ones. The black hold down ring was then slipped back into place to hold the cogs in and the agitator was reassembled. Works perfectly now and only cost $8.95 and three days for shipping.