[Samba] I need to delete orphaned objects

[Denis Morejon]

I have two samba 4.1.9 as  domain controllers.  I want to join two new 
samba servers (Current version)  as DC into the domain
in order to demote the old ones.

When I try to join as DC the first new samba, It can't synchronize 
because of orphaned objects in the samba 4.1.9.

So, I want to remove such orphaned objects first. I can't do that using 
samba-tool dbcheck --fix

Which command or tool can I use ?

Thanks in advance!