I looked at mine and it's identical to yours. I think the setscrew (s) need to be removed and then you can pull the gear off with a gear puller. If you don't have one this is the kind to buy () IMO because you may not have much room to get the other type back into the limited space. I find far fewer uses for the three armed pullers myself, but others may disagree.
?You may find the amount of force needed is less if you squirt penetrating oil on it and in the screw hole, and again it may be easier too if you heat it a few hundred degrees, standard stuff.
