If you feel that l33tness is important and you would like to do stuffs in CLI instead of GUI, no problem!!!!! Instead of using netdude, you can actually use bittwiste. What is bittwiste, it is a command line based pcap file editor that bundled with bit-twist(Libpcap-based Ethernet packet generator).
For more information, you can check out more info at it's main site, I pretty like the bittwiste reference sheet that located at
To change the destination address to 10.0.0.2, you can just run
shell>bittwiste -I /nsm/pcap/testing.pcap \
-O /nsm/pcap/testing1.pcap -T ip -d 10.0.0.2
To confirm that I have edited it correctly, I run tcpdump to check the output,
shell>tcpdump -qeXXttttnr /nsm/pcap/testing1.pcap -c 8
Bittwiste will automatically fix the checksum value as well, it is very quick and neat tool to modify pcap file indeed. Credit goes to Addy who create this interesting tool.