Post what you want to rent on the "Trade/Rent" board - there are some great FAQ's there. Since you are in the UK, you'll want to probably open a Paypal account, so you can accept payments in other currencies easily.
Don't forget to let people know:
Number of points
When they expire
Home resort
Use year
Whether they are banked or borrowed (remember, you can't transfer banked or borrowed points, but you can rent them)
To rent them quickly, you might want to try $10 a point (that seems the average, and usually the minimum too).
You could also just post the reservation - that might be more attravite to some than the points. If they rent it, you just call MS and have them change the names.
Good luck!