All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Before you attempt to ask someone else to believe in Islam, you should first have knowledge about Islam yourself. You should know the state of that person, and how to approach him. Allah, The Almighty, Says (what means): {Say, "This is my way; I invite to Allah with insight, I and those who follow me."} [Quran 12:108]
You should do Da‘wah gradually. This may take a long time, but you should be patient and seek the reward from Allah, The Almighty. Be sincere in doing Da‘wah as it could rescue you from Hell. If you ask someone to accept Islam and Allah, The Almighty, makes him accept it, you will receive the same reward for the subsequent good acts done by that person.
You can use booklets about Islam that are translated into foreign languages. You can also seek the advice of knowledge seekers and Muslim propagators you know. There are also many websites specialized in Da‘wah and you can visit them.
Allah Knows best.