Hi Chris,
The chain is a bit smaller than a regular bicycle chain. I have an inspection cover in the top of the wing located over the gear sprocket that drives the wheels up and down. I had to put the plane on jacks and then crank the gear up a bit; my master link had been hidden next to one of the gear sprockets. The chain tension adjustment screw is located in the wing root area of the wing. My mechanic was the one that actually removed a chain link and replaced the master. I hope this helps.
Allen