Work friends ask about my being a "hardcore feminist." It is easy to explain: Feminism means you acknowledge that injustice happens against women because they are women; you think injustice is wrong and want to position yourself in opposition to it.
Always remember your audience. If they are working class men, you have to account for this. People in blue collar settings don't use the same concepts or vocabulary that you're going to find in a graduate seminar. In my experience, it's best to start with other's concerns, not your own. If they are primarily concerned with getting laid, you may have some work to do before you get around to the idea of justice for women.
The fortunate thing about working with people is that you see them everyday. You don't have to resolve everything in a single conversation -- or, put differently, a single confrontation. Many activists are too quick to condemn anyone who doesn't see things their way. But if feminism stands in acknowledgment of the injustice women face, activism should stand in acknowledgment of the ignorance that stems naturally from the status quo. Rather than be surprised by it in every instance, we'd do better to be prepared.
In an important sense, you have to love other people enough to listen to them, especially when much of what they say is ugly or hateful. I'm speaking in this case of activists in the same category of power as those they interact with; in other words, as a man I have to have a measure of patience with other working class men I can't stand, at least if my long term goal is to persuade. They won't listen to women, but it's possible they will listen to another man. You always want to be pushing the possibilities in this regard, but it isn't easy; a strong sense of class consciousness helps, as well as concern for the women these men inevitably interact with.