I have an Exchange 2016 server with the DC role installed (server 2016). This DC is the 2d DC. Now a want to remove de DC role from the Exchange 2016 server. I have already installed an 3th DC. Are there problemen to remove the DC role from the Exchange 2016 server?
You cant remove the DC role when Exchange is installed on top of it.
Its a bad practice to do install both role on a server and Exchange warn in the install to not do so.
Install a second Exchange to migrate all the data, after remove Exchange and the DC role after from that server.
Demoting a domain controller to a member server isn't supported.
Installing Exchange on a domain controller is not recommended by Microsoft.
You can Demoting Domain Controllers and Domains. But removing the AD DS roles with Dism.exe or the Windows PowerShell DISM module after promotion to a Domain Controller is not supported and will prevent the server from booting normally.
I agree with @yagmoth555, like he said, install a second Exchange to migrate all the data first, and then remove the Exchange and the AD DS roles from that server.