Yes, religions change, but Islam hasn't changed as much as Christianity. Islam hasn't been modernized, but that's because Greco-Roman culture isn't part of its bedrock. "Modernization" means going back to ancient pagan humanism and rationalism.

Still, Islam does have some seeds of progress that draw on other ancient cultures and on the perennial philosophy (via Sufism, for example).

The main way of changing Islam would be to extract it from the desert mentality. Muslims who leave the desert zones not only encounter modern ideas, but they're able to think more clearly because they're not oppressed by the desert heat. Of course, people in the Middle East now have air conditioning so climate isn't as decisive a factor as it might once have been. But I suspect this point of pure geography helps explain why the Islamic world is held back from progress.