Hello!
I am not familiar with the process of editing pcaps.
But I know of some tools that might help you:
- Scapy allows one to create pcaps from scratch: https://scapy.net/
(maybe it’s also possible to edit existing pcaps with that, but I’m unware) - There’s also this, for editing (I have never used it): Tshark | Edit Pcap
Hope that helps!