Jay,look at your pictures. The shaft that is connected to the tractor needs to come off and be slid back onto the shaft that is still connected to the blower. The piece that is still connected to the tractor should have a locking collar on it. Grab the collar and slide it towards you. This should unlock it and you should be able to pull the shaft loose. The collar will stay with the piece you are removing. After you have it off, slide it onto the shaft that is connected to the blower. Now hook up the quick hitch and slide the shaft with the collor back onto where you removed it. It should click into place. Hope that helps.
What your problem is...............when you removed the blower you did not unlock the collar and the shaft seperated. You need to unlock the collar and put the two pieces back together before you install the blower.
Sincerely, Dirt