In 2017 I repaired the minds of no less than three ☭TANKIE☭s using the following technique. I should clarify that I believe this methodology is only useful for the ☭TANKIE☭s you have real-world access to. Those online ☭TANKIE☭s posting ironic memes and who believe that the over a dozen US military bases in Syria is a counter-revolutionary bourgeoisie conspiracy are too far gone to fix.
The first step is to empathize with the ☭TANKIE☭. Learn what makes the ☭TANKIE☭ prefer authoritarianism. If it's simply because they are a cop in revolutionary clothing, don't waste your time, they will eventually be class traitors.
Most ☭TANKIE☭s are the way they are due to ML indoctrination by way of lies and dogma. This is easy enough to combat. It starts by explaining to your ☭TANKIE☭ why you can never be a ☭TANKIE☭. The key here is to explain that you're an anti-capitalist and that by definition that means you must oppose state-capitalism. It'll take a lot of work over beers to convince them that you're not crazy when you say that the Bolshevik program simply replaced bourgeoisie control of production with a state-capitalist bureaucracy.
If you're unfamiliar with this then you can begin to brush up on the subject here, libcom.org
Once you get into the weeds with them begins your opportunity to begin rebuilding that poor broken brain. To start do a book exchange. Trade one book or pamphlet you want to read with one they want you to read. Of course whatever they offer you will be revisionist reactionary nonsense so it'll be easy enough to discredit. However, the four book I will suggest you have them read will destroy their existing worldview. I recommend reading them with your friend in the order listed below but I don't think it is really critical…
The Bolsheviks and workers' control: the state and counter-revolution, Maurice Brinton
libcom.org
The Kronstadt Commune, Ida Mett
theanarchistlibrary.org
Bloodstained: One Hundred Years of Leninist Counterrevolution, Iain Mackay, Barry Pateman, Mark Leier
libgen.io
The guillotine at work, part 1: the Leninist counter-revolution, Gregori Maximov
libcom.org
This is period is going to be very emotionally trying for your ☭TANKIE☭ so it would be best to only focus on one ☭TANKIE☭ at a time. They may begin to be ostracized by or disconnect from their fellow ☭TANKIE☭s which will mean you'll need to be there to reassure them they are on the right path. If you cannot commit to this they will likely break off their comradery with you instead.
Through this period thought the ☭TANKIE☭ will have shed their outer iron shell and embrace a more libertarian Marxist perception. It's not likely you'll turn them into something as radical as an anarchist but whatever the result it'll always be better than a broken tank.
Thanks for reading this and I wish you the best of luck in fixing your own tanks.