I know this is late, but...
Remove the nut from the right bearing, leave the bolts on the bearing. Unbolt the gear-shifter, and pull cotter pins as needed. Unbolt the rear plate, bottom plates, right plate (that also holds the wheel). You need snap-ring pliers to remove the small chain sprockets on either side. pull snap rings that are on the right side of the trans-axle shaft. Be careful not to deform any of them too much. Once you do this, you can disengage the wheel drive chains from the sprockets.. If you'd like, you can remove the brake disc sprocket but no need. You can remove the chain from the transaxle sprocket like you would on a 10 speed bike chain. Once you decoupled the chains and removed snap-rings.. tap out the shaft from the left side to the right, by using a bolt and a hammer. Lightly tapping it from the center of the bearing. Dont tap bearing, just the center shaft. Comes out pretty easily. If you carefully kept track of all the parts, you should be golden. Put everything back in reverse order and test. As daunting as it may seem, its not as tricky as it looks.. Don't give up!! I had the same problem..