My concern is that changing Football will be difficult, if not impossible. It would be like asking them to change the Bill of Rights because some of it is outdated. It's a religion to many Americans.
College is a feeder to the NFL. High school is a feeder to College, etc. Once you limit the source of nourishment, it will die in it's current state, but it will take a while.
It may also require coordinated action, since no one wants to be the first college to give up the cash cow. This is where action by the NCAA or even legislation would be helpful.