The real question is how to change the way the teachers teach.
This means I disagree with madmaze. Change the teachers, and the curriculum changes will follow. Change the curriculum with the same teachers, and you get New Math < http://en.wikipedia.org/wiki/New_Math >, which had some good ideas but was doomed.
Problem is, math and science degrees are a lot more expensive to employ.
The bigger problem is that you need to pay Math and Science degreed people more than other teachers because of scarcity and other high paying job opportunities. The current educational machine won't allow that.