GTM - how to change a slave zone to master

All,

 

on my pair of GTM's I have multiple zones setup as as slaves which currently take zone updates from a remote windows server. We want to change the setup to make the GTM's the master DNS servers (and the windows servers the slaves). Via the web gui on the GTM I notice the zone type can not be changed. Does anyone know how to approach this? I'm wondering if I need to drop the zone config to a file, then delete it and manually recreate it as a master zone.

 

 

Any pointers thoughts etc would be greatly appreciated

 

 

M