This website has lots of info if you really want to go legally licence free:
https://www.tvlicenceresistance.info/
It boils down to this:
Don't reply or send back any threatograms, just bin them
Don't sign anything
Don't invoke the Withdrawal of Implied Right of Access (WOIRA), it just makes yo more of a target
If TVL Goons turn up and you answer the door, Say Nothing and Shut the Door
Treat the TVL as you would any cold callers, which is basically what they are.