I don’t know any Sikhs where I live, but this article is insightful and good to pray about.
Christians where I live often tell Sikhs that if they accept Jesus, they have to get rid of all their gods, cut their hair, and stop going to the gurdwara. Please don’t make that a point of emphasis when you share with them. Wait for the right time, explain relevant Scripture to them, and let them make the decision to remove images of their gurus or leave their house of worship. Allow the Spirit to move, and let the Bible speak for itself. As they’re being renewed in their faith, they will be able to make some strong decisions for Jesus.