Help with Pulver Cops and Robers machine

[Jackpot]

I need a little help with the Pulver cops and robbers gum machine. I need to change the main spring, I have one but can't figure out how to remove one end or the other on the main gear, I need to do this to get the clock works apart to change the spring. I am wondering if I need a small gear puller or something. Does anyone know about such things? Which end of the main gear do I work with and how to remove it? This gear is the gear with the large washer looking eccentric on one end, the other end has a hook like looking thing that is a guide for shutting the mechenism off.
Thank You
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