Islam can not change, it will not. Changing the word of Allah can not happen.
Read the Old Testament of the Bible. It's pretty rough at times. Do we condemn the Jew because of the rhetoric of the OT? I think not. There is much beauty and truth too in the OT.
All you have to do is look at the several different sects and see that they can "interpret" the Koran any way they want.
I think you are missing the point that it already has changed. You could say catholicism can't change, but it has. You could say that protestantism can't change, but it has. The word of God never changes, but our understanding of it does.
The Muslim religion is a false religion, but being of man it is subject to the folly of man -- and one folly of man is to adapt things to his own greed and selfishness.
True Islam is way too hard for the soft underbellies of the modern enlightened man, and so it has changed in cultures where there is freedom and money and materialism.
Many american muslims abhor what they see being done to what they call their "religion". The true believer muslims hate what we have done to their religion -- it's one of the things that drives them to want to destroy us.
So while a true muslim as defined by the original intent of the Koran is an enemy of both the True God and mankind, there are large bodies of "muslims" who are no more adherents to their faith than are half the people in this country who call themselves Christians.