Change admin on Hub C-7

[bobbyD]

Please see the following thread. The previous owner will have to de-register the hub:

How can I remove the email address of a previous owner?

Hi Guys, Recently bought a (secondhand) C7, but there is a admin account via the sellers email linked to it. I would like to remove this, but of course I dont have access to this mail address. In the topics there was some info regarding a hidden factory reset option, could somebody help me out? BR Martijn