If a new generation who can think, say, and write whatever they wish should appear, the rest would fall into place, but the upheaval would be comparable to the Protestant Revolution and the ghastly religious wars that accompanied it.
Yes it will be ugly, but it's inevitable I believe.
It would not any longer be Islam.It would be apostasy to a very different religion or to areligious modernism. The Reformation, violent as it was and extreme as were the antipathies, did not change the basic beliefs of Christianity. A "Reformation of Islam" that allowed Moslems to become modern would be a wholesale abandonment of the basic beliefs of Islam. Christianity was never a rigid system that encompassed every faced of government and law. It, in all its variations, delineates and prescribes man's personal relationships with God and his fellow man and says nothing about government. Islam in its holy book prescribes submission to allah and the moslem ruler and makes no allowance for anything like democracy or any sort of republic and enjoins constant warfare and conquest. It can be "reformed" and has been reformed- see the Shia- but the reforms can only address who is authorized to rule. Islam cannot become tolerant or modern.