I recently acquired some new prop adapters from 3DR. see http://store.3drobotics.com/products/propeller-fastener-and-shaft-kit-for-blue-moto-1
They require you to replace the motor drive shaft which is simple but not uncomplicated task. To help anybody who wants to do the same I have created an Instructable (see http://www.instructables.com/id/How-to-change-the-drive-shaft-on-your-Quadcopter-R/ ) with the use of minimal tools.
I look forward to comments on how I can improve it.