What is the Model of the AP having an issue? If its a RAP device the user should be able to use a Pin to reset the device, and by plugging it in the use should be able to provision it again by pointing it at the RAP Controller.
If its a Campus AP which has be provisioned in RAP mode, I'm not sure if there is any way to reset it remotely. Maybe something via console, but if its a end user, that is probably not an option.
-ELiasz