Huh?

If it makes it's money off ads, you send corporations pictures of their ads being shown with shit they don't want associated with.

If the corps care, they stop paying ads.

Then the social media reigns in the nazis to get ad sales up.

Other than that, get people (including yourself) to just not use social media that's full of Nazis. Even if you think you're "fighting the good fight" if they don't have a "them" to attack, they'll attack each other.

All being there does is give them someone to unite agains

Find content that is against their service providers TOS and report them. Don't have much of a platform if the host / CDN doesn't want to have them as a client.

I don't think you'll get anywhere with a single tactic. Organizing, as with life, works best with diversity. In this situation, I'd probably start with some subvertising; defacing their ads to convey the message.

Someone who doesn't even have the balls to name and shame the forum won't be able to do anything. But in all honesty, comedy is the only thing that works.

The alt-right innately functions on relief.

They thrive off people feeling disgruntled and under represented by the system, feeling overlooked and alienated. People who have grievances.

...and then they provide those people with an identity, community, and a sense that someone is listening and will represent them.

That person is usually seen as a capable outsider who bucks the system and "gets them" showing this by being charismatic and funny. Someone who swims in the same waters/thoughts as them.

You'd have to break and replace all that, show them who "their guy" really is whilst being funnier and more charismatic. It's really tough to do and will need more than just one person.

Use Cuck porn

Use alt-f4