Get a big pry bar, put a penny between the pry bar and the sheave shaft to protect it and pry the seat frame away from the motor. The motor is rubber mounted and the seat frame will bend slightly but not permanently. At the same time you are prying, the secondary clutch will just clear and you can pull it out. If you have a large solidly mounted vise and a stock steel front wheel, you won't need to buy the spring compression tool. Put the clutch in the vise on the large nut, and twist the whole clutch until the nut comes loose slightly. Now place the wheel over the clutch exposing the nut out of the center of the wheel and stand on it, compressing the spring. Spin the nut off and slowly step off of the wheel. Now you can replace the spring. Just reverse the steps to put everything back together. It goes a lot easier if you have a partner to help you.
One hour from Glamis!