Have you tried simply moving it up? Meaning; pivot the arm connecting the mirror to the windshield up. However, you'll notice that as you move the mirror higher, you won't be able to see as far behind the car since the slope of the roof will cut off the line of sight. It's a toss up - if you keep it low, you can see further behind the car, but obstructs more of the windshield - if you move it higher, you will have more windshield, but less rear view area.
Changing it out would involve breaking the glue seal and then removing the base from the windshield, unless your new mirror can somehow use the same base piece.
Personally, I keep mine as high as I can get it and deal with the limited rear view area. I try to compensate by angling the side view mirrors a little higher. I wouldn't want to give up the compass and the auto-dimming feature just for a little bit less windshield obstruction.
