Description of problem:
Recently "Replacing controller nodes" has been updated.
However, we see that several procedures to use the same BMC IP address to new node were removed,
and I believe these procedures are still necessary.
Please refer the bug 1632530 , which initially introduced these procedures into old version doc
We can find the detailed steps in https://bugzilla.redhat.com/show_bug.cgi?id=1632530#c17 .