[Samba] Replace primary DC

[aere_premium.0k at icloud.com]

Following this thread:
https://lists.samba.org/archive/samba/2025-April/251400.html

We currently have 3 Samba (dc2, dc3, dc4) currently installed as
secondaries for dc1, they are installed from debian 12 backports while
dc1 is from a Turnkey Linux using an old version of samba, webmin,
etc...

I'm thinking about reinstalling to homogenize the infra. Is this the
right way to do it:
- Transfer FSMO from dc1 to dc2 (or another), backing up idmap.ldb and sysvol
- Demote and shutdown dc1, removing any leftovers from dc1 in LDAP and DNS
- Reinstall dc1
- Put back sysvol and idmap.ldb
- Transfer back FSMO to dc1

Thanks
--
Regards, Adnan R