Broken……..very briefly……first I recommend a shop/service manual but here is the procedure. Remove the hydro line from sheave, pry open 'jackshaft' sheave and drop a 5/8 or 11/16 socket into the sheave to hold it open, work the slack in the belt to the variable speed/crankshaft sheave and squeeze the two sheave halves together exposing 3/4 to an inch of the 'roto-swivel' assembly. Next slide the cap (washer looking) back onto the shaft and that will expose an external lock ring on the shaft that fit inside the cap. Once you have that all off refer to the thread started by bobcat88.