The tactics for doing so are extremely crude and apparently quite successful. Anyone can practice the first stage of myth-making. All you have to do is find an argument you disagree with and call it a myth. The second stage, repetition, is more important than the first. Repeating the myth-label is a defensive tactic.
Amplification is the offensive counterpart to repetition.
It helps if you have a lot of money or a lot of access to opinion leaders in government, corporations and the media. The point of amplification is no longer simply to dispute the errant idea, but to drown it out entirely in a wall of unanimous noise. But whether or not this will be successful depends on the size of their megaphone. It is a game they are sure they can win. And it's the game they play the most.