Image below is borrowed from IGN's guide for the 3DS version. It's the same solution here so...
This really is a simple puzzle, but here's a small guide to make it even easier if you're having any kind of trouble.
First, pull both levers once that are on the platforms to the right and left just above the second level.
Second, position the four movable mirrors as seen below.
In case the image every gets taken down, here's a textual guide for placing the mirrors.
First Mirror - 1st (bottom) Level - After pulling both levers, position this mirror below the first globe the beam comes in contact with when dragging it to the left.
Second Mirror - 2nd Level, Right Side - Push this mirror all the way to the right.
Third Mirror - 2nd Level, Left Side - Position this mirror below the left most globe on the 3rd (top) level.
Fourth Mirror - 3rd (top) Level, Left Side - If needed, position this mirror so the beam hits the ceiling mechanism.