My organization shelled out for a gTLD, and we currently use 3rd party (Verisign) to host it on their DNS servers. However, there are 2 issues: we pay quite a bit for that yearly (that's the lesser issue); updating data there is... convoluted (also for our organizational reasons).
However, we run quite huge DNS system for our other (non-TLD) domains. I have tried searching if it's possible to self-host gTLD, but while I found some info for new gTLDs, I haven't for transferring existing gTLDs.
Can anyone point me to some overview/howto/readme, or can just speak from experience?
EDIT: for sake of having a reference point, let's say I already own .example. gTLD. Currently it is maintained on Verisign DNS servers. I want to be able to maintain it on my own DNS servers.