No man can convert another. To become a Christian requires a heart that God approves. (See Jeremiah 17:9, 10) If any have the desire to be approved by God then they must follow the direction at Proverbs 3:23 to safeguard the heart.
How can a person guard their figurative or inner heart from being contaminated by; wrong desires; spiritual apathy; being mislead by the world under the control of the devil; and more? Any can IF they choose to become a person desirable to God.
If a Muslim has actually read the Qur'an then he must also be aware that the Bible is inspired of God and cannot contain error. The Qur’ān calls the Torah and the Injīl “the Book of Enlightenment.” (Āl ‘Imrān [3]:184; Fāṭir [35]:25) Scores of Qur’ānic verses state that these books are from God. (Al-Baqarah [2]:89; Al-An‘ām [6]:92) Concerning both the Torah and Injīl, we read: “Wherein is guidance and a light.” (Al-Mā’idah [5]:44, 46, MMP) Furthermore, Al-Mā’idah [5]:46 says about the Torah: “Therein is the (plain) command of God.” Many of the great interpreters (such as Al-Jalālayn, Al-Fakhr Al-Rāzī, Al-Ṭabarī, and Al-Bayḍāwī) acknowledge that according to the Qur’ān, the Torah is called “the Book of God” (Āl ‘Imrān [3]:23) and “the Book which helps to make things clear.” (Al-Ṣāffāt [37]:117) Nevertheless, some still believe that the present-day Torah and Injīl have been corrupted and cannot be trusted. But if this were true, when did this falsification take place?
From a Qur’ānic viewpoint, no corruption could possibly have occurred before the writing of the Qur’ān because many Qur’ānic verses call for faith in the Torah and the Injīl. (For example, see Al-Baqarah [2]:136; Āl ‘Imrān [3]:84; Al-Nisā’ [4]:136.) The Qur’ān also recommends seeking out those versed in the Torah and the Injīl, saying: “If ye realise this not, ask of those who possess the Message.” (Al-Naḥl [16]:43; Al-Anbiyā’ [21]:7) Would it do so if these texts had been corrupted? Furthermore, many Qur’ānic verses call out to “People of the Book” (the Torah and the Injīl) to turn back to their books. (For instance, see Al-Mā’idah [5]:50, 71.) Surely, an invitation would not be given to turn back to corrupted books!
Bottom Line
A Muslim can become Christian IF they choose to be a person approved by the Almighty God. No man can force real conversion, period. A person must want to change. That is called free will. And free will is a gift from our creator.