Step 4: The <nodename> in the trap_dest line is the node where you will be receiving the SNMP Traps.
Steps 5 & 6: Apply to the node configured as the traps destination.
Assign the SNMP Trap policy to that node.
Then for all source nodes, make sure your selected node is configured as a trap destination. (currently your OMU 8 server with NNM will be configured as the trap destination) Most of your traps are probably coming from network devices, not servers.
If your existing OMU/NNM server is going to be de-commissioned at the same time as the new server is brought on line, you could save some work by putting a new node at its IP address and using it as your trap receiver.