So to remind you, here was the original, chunky white framed mirror.
Measuring out where these should go was the tough part so after we got them up and level we just stood and stared at them for a moment. They are pretty cool how they work too - the base brackets are stationary but the top brackets have a little spring in them that allows you to put the mirror in the top, push up to contract the spring, slide the mirror down into the lower brackets, lower the mirror, and the springs hold it back tightly in place. We thought they were really cool.