I need to remove an old server from the tree. Will ensure it does not
contain the replica. This server is the Organizational Certificate
Authority and also the Security Doamin Key server. Can I easier move the
above to a NW 6.5 server or I have to delete the security object and
recreate everything again?

If I delete the security object, would it cause problem on the servers that
are already installed in the tree?

Any help would be appreciated.