I just know it is not easy and straight forward. Requires moving the center variator sheaves, IIRC
Have you searched the net for the "how to" ?
When I had a model 212, IIRC, I changed out the belts. Hoisted up the front end without the mower deck, and essentially stood it up on its rear wheels (used a chain fall again IIRC).
I had easy access to the variator and parts I needed to either remove or just loosen.
Google these words "Replace drive belts John Deere 216 variator" and several hits come up that should help you.
Thanks check now.