The technique he used, where you find a dead baby around the same age as you and assume their identity is called the Jackyl method.https://www.rte.ie/news/2024/0422/1444983-passport-cork/ What’s the story with this guy? Hardly looks like he attempting to overthrow the state.
Frederick Forsyth learned about from some merc in the 60s and laid it out step by step in Day of the Jackyl.
Apparently it was a well used for years afterwards right up until biometric passports came in