Be alone with one, in a friendly, relaxed situation. Disarm him or her with friendly banter.
Then this or similar:... "[their name], I know you are a Muslim, and I would never think of trying to convert you to anything else. But do you, as a Muslim, believe that other people should be free to believe in their religions too, whatever they may be, Catholic, Jew, Hindu, Presbyterian, Baptist, and so forth? Watch their eyes. Listen to their response.
The first Muslim I asked the question regarding other religions had been a friend for around six months. He was about as "moderate" and a friendly Muslim as you'll ever meet.
He was well educated, a Colonel in the Egyptian army, his wife a surgeon.
When I asked him the question, you should have seen the look of pure chilling hatred that came across his face. He looked me right in the eye. His response: "There is no God but Allah, and Muhammed is his messenger".
Then he went right back to normal.
Every non Muslim (infidel) needs to read a true translation of the Holy Quran or Koran. Then they might understand why this is happening and why it will never stop happening.
IMHO these are probably the most accurate translations, and they are FREE.
appreciated