**Ok when reading the Quran I see nothing about death to an apostate. I only see Allah will punish him. **
“But those who reject Faith after they accepted it, and then go on adding to their defiance of Faith,- never will their repentance be accepted; for they are those who have (of set purpose) gone astray. As to those who reject Faith, and die rejecting,- never would be accepted from any such as much gold as the earth contains, though they should offer it for ransom. For such is (in store) a penalty grievous, and they will find no helpers.” 3:90-91
"Those who believe, then reject faith, then believe (again) and (again) reject faith, and go on increasing in unbelief,- Allah will not forgive them nor guide them on the way." 4:137 "A section of the People of the Book say: “Believe in the morning what is revealed to the believers, but reject it at the end of the day; perchance they may (themselves) Turn back… " 3:72
"Any one who, after accepting faith in Allah, utters Unbelief,- except under compulsion, his heart remaining firm in Faith - but such as open their breast to Unbelief, on them is Wrath from Allah, and theirs will be a dreadful Penalty. This because they love the life of this world better than the Hereafter… Without doubt, in the Hereafter they will perish.” 16:106-109
**I read in the Hadith something totally different than what was written in the Quran. **
“Allah’s Apostle said, The blood of a Muslim, who confesses that none has the right to be worshipped but Allah and that I am His Apostle, cannot be shed except in three cases: In Qisas for murder, a married person who commits illegal sexual intercourse and the one who reverts from Islam (apostate) and leaves the Muslims.” 9:83:17
Narrated 'Ikrima: 'Ali burnt some people and this news reached ibn 'Abbas, who said, “Had I been in his place I would not have burnt them, as [Muhammad] said, ‘Don’t punish (anybody) with Allah’s Punishment.**’ No doubt, I would have killed them, for [Muhammad] said, ‘If somebody (a Muslim) discards his religion, kill him.’” 4:52:260 **The legal regulation concerning the male and the female who reverts from Islam (apostates). Ibn 'Umar, Az-Zuhri and Ibrahim said, "A female apostate (who reverts from Islam), should be killed. And the obliging of the reverters from Islam (apostates) to repent. Allah said: — ‘How shall Allah guide a people who disbelieved after their belief and (after) they bore witness that the Apostle (Muhammad) was true, and that Clear Signs had come unto them? And Allah does not guide the wrong-doing people. As for such the reward is that on them (rests) the curse of Allah, the Angels, and of all mankind. They will abide there-in (Hell). Neither will their torment be lightened nor it will be postponed (for a while). Except for those that repent after that and make amends. Verily Allah is Oft-Forgiving, Most Merciful. Surely those who disbelieved after their belief, and go on adding to their defiance of faith, never will their repentance be accepted, and they are those who have gone astray.’ (Sura 3:86-90) Bukhari Volume 9, Book 84, Chapter 2, p. 42-43.
57. Narrated 'Ikrima: Some Zanadiqa (atheists) were brought to 'Ali and he burnt them. The news of this event, reached Ibn 'Abbas who said, “If I had been in his place, I would not have burnt them, as Allah’s Apostle forbade it, saying, ‘Do not punish anybody with Allah’s punishment (fire).’ I would have killed them according to the statement of Allah’s Apostle, ‘Whoever changed his Islamic religion, then kill him.’” 9:84:57
If the Quran is the final word but yet clearly disagrees with the Hadith than it seems people who follow the hadith are misled and committing apostasy themselves. Why would the Hadith need to correct the Quran if the Quran contains ‘the final word of God’?