You can use Interactive SQL to change the name of a multiplex server.
Prerequisites
Although you can run the
ALTER MULTIPLEX
SERVER command from any server in the multiplex, it is recommended that,
like all DDL, commands be run on the coordinator. Except when altering role from reader
to writer, the named server automatically shuts down once the change commits.
TaskStart the server, connect to it, and issue a
command in the following format: ALTER MULTIPLEX SERVER oldname RENAME newname
This command renames and shuts down the named server.
An alternate method is to right-click the server and select
context menu Control > Include/Exclude.