Hi
Islam/Quran/Muhammad do not define “any five major branches of Islamic law” so it has no basis from Quran/Islam/Muhammad.
For apostates/apostacy kindly peruse following verses from Quran together with the context for undersanding the true Islamic/Quranic/Muhammad’s concept, not of his followers who may be wrong:
The apostate cannot harm the true religion, he can only harm himself -------3:145.
GodAllahYHWH promises if somebody leaves Islam out of free-will, that He would compensate and give a large party in that person’s place, so there is no need of harming such a person------5:55,
There is absolutely no punishment for the apostate in this world by hands of the Muslims, he would receive it in the hereafter -------3:90,16:107, 4:138, 2:218, 5:55.
I think you would understand.
Thanks