I know this is an old thread... but for the sake of anyone else that finds it... the deck pulley has an allen bolt that has to be removed to slide it off. It does show up in the illustrated parts manual for the country clippers.
It's quite easy once you figure it out. There is a collar around the rear yoke that slides one way or the other. It is spring loaded so it takes some coordination to pull on the driveshaft and work the collar but after you get it you won't forget it. a little penetrant on the shaft helps too. Good Luck. Matt