Those 90 tooth rear sprockets on the Schwinn electric scooters can be on there very tightly. They loosen in the counterclockwise direction. You can make a tool to remove them from a two foot 2x4 and a couple of 3/8" bolts like in the illustration below.
With the homemade tool you might be able to remove the sprocket if someone holds the wheel steady. If that does not work then you can put an old pair of bicycle forks in a table mounted vise and use the forks to hold the wheel steady when removing the sprocket.It also would not hurt to soak the threads in penetrating oil for a few hours or overnight before attempting to remove the chain sprocket.
William
I have a Schwinn s750 scooter,need to remove the rear wheel threaded sprocket,but it won't budge! What am i missing? I know it should be tight,whats the best way to remove?