The quoted verse is abrogated by the Quran. And the no compulsion in religion applies to a verse talking to the Israelites. It seems you have reading comprehension problems or are ignorant of Islam. It clearly says, that Mohammed said kill those who leave Islam.
"Let there be no compulsion in religion" Surah 2:256
"Therefore expound openly what thou art commanded, and turn away from those who join false gods with Allah" Surah 15:94
These verses seem to say clearly enough that the Qur'an teaches a peaceful response to those who oppose Islam. But there are other verses in the Qur'an which say quite the opposite. For example "But when the forbidden months are past, then fight and slay the pagans wherever ye find them, and seize them, beleaguer them, and lie in wait for them in every stratagem (of war); but if they repent, and establish regular prayers and practise regular Charity, then open the way for them: for Allah is Oft-Forgiving, Most Merciful"
Surah 9:5
Which verse should Muslims follow? According to the doctrine of abrogation, the later texts supersede the earlier whenever there are inconsistencies, or they are said to "abrogate" the earlier texts. Therefore, a Muslim simply needs to know which verse came earlier, and which came later.
Surah 2:190;2:256 & 15:94 have all been abrogated according to Muslim scholars.(تراجع كتب الناسخ والمنسوخ لـ ابن حزم، الكرمي، ابن الجوزي، المقري، قتاده،...) (for detailed information check books under titles like The Abrogative and the Abrogated by authors like Ibn Hazem, Al-Karmi, Ibn Al-Jawzi, Al-Muqri, or Al-Nisabouri)
Suyuti in his book استنباط التنزيل (Istenbat al tanzeel) says: "Every thing in the Qur'an about forgiveness is abrogated by verse 9:5." Al-Shawkani in his book السيل الجرار (Alsaylu Jarar 4:518-519) says: "Islam is unanimous about fighting the unbelievers and forcing them to Islam or submitting and paying Jiziah (special tax paid only by Christians or Jews) or being killed. [The verses] about forgiving them are abrogated unanimously by the obligation of fighting in any case."
To anyone acquainted with Islamic law, it is clear that according to Islam, the punishment for a Muslim who turns to kufr (infidelity, blasphemy) is execution, and the following article thoroughly documents this from Islam's source documents.
"THE PUNISHMENT OF THE APOSTATE
ACCORDING TO ISLAMIC LAW"
ABUL ALA MAWDUDI
http://www.answering-islam.org/Hahn/Mawdudi/