This is not a simple task without deployment manager. You have to do it via scripts. IBM provides this scripts for free but they are not easy to find :-)
and you are looking for ConfigScripts.zip
To rename it:
/usr/IBM/WebSphere/AppServer/profiles/AppSrv01/bin/ws_ant.sh -profileName AppSrv01 -buildfile exportImport.xml -logfile rename.log -DoldServerName=server1 -DnewServerName=server2 -DnodeName=yourNode01 changeServerName
I would expect this to be a much easier process but IBM obviously doesn't share my ideas...