VNX Usermapper Secundary Changing in Primary.

Hi,

In our enviroment we had two VNX5300 systems, the one with the primary usermapper is completly shutdown and decommissioned.

So the one still running has readonly usermapper database and new created AD users are not able to access shares.

Question is how to change the usermapper to primay without breaking things, like ruining for accounts existed  before removing the other VNX.

Kind regards.