That piece with the wheel on it is supposed to not ride on those peg looking things, but under the star. Pry that lever with the wheel on it, down, and push in on it at the same time to make it go under the shift star. If you can't, more than likely looses the screw holding it, and that is causing it to not go under the star. The screw, and that arm, go into each other. Look on the underside of the screw, where the washer is. it has a round spot sticking out that slides into the center of that shift arm thing...not sure what it's called. It takes a little time getting it in there, but you can get it.