Maintenance PRM for MR-SC102T

Hey all.
I hope someone is able to help me with this problem I have.

I have a machine with 2 MR-SC102T servodrives.

One has been replaced with a refurbished unit, but for some reason the maintenance parameters in the two differ, and due to that I'm getting AL 37, which indicates a broken maintenance parameter.

I have figured out how to change the User and the Special parameters, and how to view the maintenance parameters, but there is no where in my manual that explains how to change the Maintenance parameters.

I really hope someone can explain how to unlock them?

/Lene