The US was a vastly different country in the 1960's than today from all points of view. Plebs had way more social cohesions and unity, and lot more bargaining power over the wealthy and politicians, when communism was the main enemy and all working class jobs hadn't been yet shipped abroad and PE hadn't yet monopolized ownership of housing and everything else and the US industrial elites didn't have doomsday bunkers in Hawaii and New Zealand.
What I'm saying is what worked then won't work now because the context is completely different.
The same way it’s always done: political organizing. Find groups that are working towards the world you want and start chipping in and getting involved. It takes time, there’s no magic wand, and we should’ve started 20 years ago, but none of that changes the answer: if you want the world to be different, get out there and start doing the work.
And, it has worked - it worked in the 30s to get the New Deal through and expand unions, it worked in the 60s to advance the environmental and civil rights agendas, it worked in the 80s to dismantle the New Deal, it worked in the 90s to promote gay rights, it worked in the 00s to make Christian Nationalism a national political force, it worked in the 10s to get a fascist elected and then re-elected, and god willing it’ll work in the 20s to get these fucks out of office again too.
Then organize like every other movement; study the US in the 1960s.