There are Muslims who believe that Islam can reform but they too are deluded:

FaithFreedom.org,
Why Can't Islam be Reformed?

This is the position of many modern Muslims, including Irshad Manji the author of “What Is Wrong with Islam, Today”. A great number of Muslims realize there is something wrong with Islam, but they erroneously believe the problem can be solved through the miracle of reinterpretation; and that they can keep the Quran and believe in Muhammad but somehow do the opposite of what he did and said and still call themselves Muslims.
...
You ask: "Can Islam be reformed?" No, it can't! To reform Islam you have to first get rid of Muhammad and second get rid of the Quran. You have to take out a great portion of that book which is violent. The rest is nonsense and absurdity. But this you can't do, because you have no authority to do such a thing. Muhammad said that he has perfected his religion (Q. 5:3). How can you improve something, which is perfect? You can't change the Quran. You can't reform it. All you can do is to reinterpret and, for example pretend, "slay the unbelievers wherever you find them" means something else.

Then there is the website Muslims Against Sharia who argue that the Quran is not the literal word of Allah; that Islam, in its present form, is not compatible with principles of freedom and democracy; that Muslims must remove all the evil passages from Islamic religious texts; that there is no one religion that is superior to another; that Sharia Law must be abolished; that Seventh Century practices such as stoning, cutting off body parts, marrying and/or having sex with children or animals must be condemned; and hundreds of other suggestions to make Islam more like Christianity or Judaism.

If somehow one could actually change one letter of a book whose wording letter for letter was fixed by no one but Allah, and dutifully followed the advice of Muslims Against Sharia and actually purged Islam of all of its barbarity then we would have in our hands a slim book with the Title "The Quran" and a sole, blank page bound in leather.

But this would not be enough, the other leg of Islam, the Sunnah is the second source of Islamic jurisprudence without which one cannot practice Islam. The Sunnah: the way of the prophet, his sayings, deeds, etc. One could compare these two legs of Islam to Christianity: the Quran, or the word of God, is like the Old Testament, and the Sunnah, or the deeds and sayings of Mohammed, are like the Gospels: the sayings and deeds of Jesus.

But while the deeds and sayings of Jesus are of humility, love, and peace, the deeds and sayings of Mohammed are of narcissism, hate, and military conquest. While the message of Jesus is "Let him who is without sin cast the first stone," the message of Mohammed is "Stone all those who disbelieve." No, I'm afraid that all of the Sunnah must be purged as well.

"But," you may protest, "if we remove all the evil from the Quran and excise all that is vile in the Sunnah, then there will be nothing left to follow in Islam!"

Precisely.

As to what happens to Muslims who try to practice even the slightest deviation from the absolute written word of Allah:

Reuters,
28 Apr 2008,
Hardliners torch "heretical" Indonesian mosque-police

Hundreds of hardline Indonesian Muslims burnt a mosque early on Monday belonging to a sect that has been branded heretical by most Muslims, police said.

The attack in West Java's Sukabumi district came after a government team recommended this month the Ahmadiyya sect be banned because its teachings deviate from the central tenets of Islam.

I believe that the government in Indonesia has a perfect right to ban a religious group because its teachings deviate from the central tenets of Islam.

I believe we in America and Europe should follow their example and likewise ban all of Islam because its teachings deviate from the central tenets of modern civilization.