Remove slave server in a multi-server setup

[binaryrogue]

I currently have two ISPC3 servers in a multi-server setup running for years and it's been great!

The first server acts as the master server where I control everything from the gui. The slave server main function is just DNS. I want to decommission the slave server and make the master server take control of the DNS.

What is the most efficient way of doing this?

Can I just go to the DNS tab on my master server and change all my DNS entries to point to the master server? Can I power down my slave server at this point?