I install new servers to the tree. Now I try remove old crashed server, but can't. From iManager error reply :

NCP Server Deletor:The NCP Server is up and running and cannot be deleted. Down the server before deleting the server object.

I check server settings and found, that I set the same IP address to another server. This server is replica Master.
Can I modify IP adress of crashed server, or how do I delet it ?