Ok, go in the side of the transmission thru the opening for the sidecover. Take a sturdy screwdriver or prybar and make sure the tip of it fits between the teeth on one of the main gears towards the front of the transmission. Then you can gently pry upwards or downwards against the case of the transmission to turn the gear cluster. You may need to use a block of wood between the handle of whatever your using to pry with to get enough leverage to turn things. Just be gently and don't get carried away so you break off teeth inside the transmission. The rear wheel or wheels will turn when you turn the transmission over. Just go a little bit at a time, and use lots of penetrating oil on everything.
