I tackled the same thing for the first time last month. They were tough to get off and I don't have a gear puller like Zeracer suggested. That's the right way to do it. (I almost went and bought one.) I sprayed penetrating oil onto them very carefully...and went in for lunch. About an hour later, I pulled and gently tapped with a rubber mallet and they came off. I just tapped tapped tapped and pulled gently. There are splines on that piece that get welded together after a period of time. Might need a second soaking with a penetrating oil.
Sorry I didn't take any photographs.
My goal was to clean the drains and look at the alarm module.
Good luck with it. PM me if there's anything I can do to help.