[Samba] demote a DC and AD without ntp

[Felipe_G0NZÁLEZ_SANTIAG0]

Hi pals, I have two questions: 
1. Can I to install a DC Samba4 without ntp. (I know Kerberos requires the time synchronization between clients and users, BUT what if I synchronize them manually?!! Is it possible log on in the clients if them have the same time that server?) 
2. I installed a DC Samba4 in a server without replication, that server is the only DC on the network. So, when I tried to demote it system says that I can NOT , because it is the latest server on the network according the FSMO roles. Then, how can I uninstall the Active Directory in that server?