Currently red-pilling a liberal communist sympathizing barista.

It's all about recognizing where they are and crafting the message to go down smoothly from their point of view. If you just rant about liberals and brown people they will reflexively become defensive. You critique judeo-capitalism without naming it explicitly. Critique the right wing Israel lobby, AIPAC. Show examples of corruption. Their minds are surprisingly fertile. When they encounter reality they compare it to the beliefs they have been exposed to. When you teach them truth, reality will back you up and reiterate the lesson.