How do laser/led projectors make green light

[Benm]

If lasers are more efficient, wouldn't the smart move to be, getting rid of the red led, and replacing it with somthing like the 500mW midsubishi red laser diodes?

Perhaps eventually.

But you need to consider that the technologies to produce those leds/lasers are often patented, and the cost of a patent licence can easily offset the additional production costs involved in taking a different route.