Ask them to define racism.

Most of the time they will give you the older definition common before progressivism. They might say, "racism is when you pre judge someone on their immutable racial characteristics and not their merit or character" or "Racism is when you hate other racial groups because they are different." If either of those are their definitions they will be easy to work with. If they say, "racism is privilege plus power" you can still work with them but you need to exclusively try to redpill them on Jews. If they say, "racism is privilege plus power, white people have systemic power, and Jews are fellow white people" I'd say just back away slowly. Especially if it's a jew.

The easiest group to redpill are the people that say there's no such thing as race. These people are regurgitating the 'blank slate' propaganda pushed in the 80's and 90's. They are multiple levels of cultural marxist brainwashing behind the curve.

As a former 'open minded' 'listen to all sides' liberal my baby first redpill was getting a lot of exposure to how black really act in society (and seeing liberals AND conservative white bending over backwards to cater to them). As a young person I had some experience with bad black behavior but was able to block it out with liberal programming. My second baby redpill was looking at white demographic decline. Anybody that has compassion will have some type of emotional reaction when you show them that whites are on a steep decline and might not exist in a few generations. Start there. Find people that don't want to see whites disappear from the face of the earth. If you are dealing with someone that's cool with that tell them to fuck off and if they call you a racist so be it.