You can list it here on TUG in the appropriate sub-forum, Craigslist, Redweek, etc. TUG has several threads on how to rent out a week, it will work the same for a MROP week. Just reserve the best week you can (best rental value) and advertise that specific resort and week. You can reserve weeks up to 18 months out, my week actually has priority at one resort allowing reservation up to 20 weeks out.
Reservations can now be made through the VRI owner's portal on vriresorts.com
I have rented out my MROP reserved week 3 times in the past decade. You can call VRI (who provides management for MROP) and add the guest's name to the reservation; there was no charge for that back then. After my renters signed the rental contract that I provided, I sent the renter the reservation with their name as guest (with my membership number blacked out).
What you net in rental charge should cover your maintenance fee for high demand weeks, prime weeks may even get you more than that ... although with rising MFs neither is as 'automatic' as in years past.
VRI does offer a program to 'rent out' your reserved week but I have no idea how that works or if its a reasonable deal.