With time. Some will attempt to educate themselves online and realize that Bitcoin is not a scam, some will FOMO in at some point in the next huge price rise, while some will pridefully think that Bitcoin is a scam no matter what happens. There are enough material online for Bitcoin education; just let Darwinism take its course.
That's the most passive approach in my opinion but wouldn't it be better if we as a community at least try and continue to educate as much people as we can reach, remember that it's better to move even though you're losing than not doing anything.We need to educate people about bitcoin.
The more people know about bitcoin, the quicker we will have adoption.