This is essentially a full recovery to a new system. You probably should begin with the appropriate copy of the Backup and Recovery manual from the <a href=”http://publib.boulder.ibm.com/infocenter/iseries/v5r4/index.jsp?topic=/rzaiu/rzaiurecover.htm”>Recovering your system</a> topic for your version of the OS.
You can follow the procedures from Appendix D., Recovering Your Server to a Different Server, in that Backup and Recovery guide.
There is no “easiest way”. This is a complete build of a system if the partition is empty. Follow the checklist closely.