How will you

Try to be an example and have knowledge about the religion is a good start. If the person does not have an open mind or at least takes the first steps of curiosity, then chances are much slimmer. People have layers of learned behavior that shield them against accepting new ways of life, especially when they hit a certain age caused by external factors.

I almost made a Chinese guy Muslim by accident as a teenager (no effort, really), but then he returned from a trip from China and said he became a Buddhist.