I haven't done that servo, but I think you can do it.
Since its MG, that means it has a metal pin in the big gear that you need to take out. Its press fit in really tight, so its kinda hard to pull out.
If you put the gear in a vice, and get a small needle and hammer, you could hit it out. Or use pliers and struggle till it comes out
If you still aren't sure, just take some pics and post them. I can help you.