What would I do with a 300 hr pilot, flown years ago, in the right seat?
Comm? Into ORD!?!?! Absolutely not. "Listen to the radio, back me up with the altitudes, headings and freqs assigned."
I'd point out the radios, mic selectors, speaker volume, auto pilot and auto throttles, along with a very brief overview of the MCP and FMC. Basic overview in the event something stupid happens to me.
Gear and flaps? Nah, it would be easier to reach over and do it myself as opposed to having to teach ground school at 200+ kts.
Final 3 green - the plan would be to have you set up the a/c for an autoland. Hand flying the a/c to a landing, with low experience, is too risky.