Private PUBG ESP using packet sniffing.

Looking for a personal "hack" to sniff the incoming packets (UE4, UDP) and give information about the location of players. I'm a programmer myself (albeit no network experience in the slightest) and would like a basic explanation of how it works, and what it takes to find player addresses so I can further modify it if I so choose. It should be completely external, not touching/modifying/manipulating game data at all. Reading packet data only. I plan on attacking this to a LAN connector to run on an external machine eventually.