Basically all I do is use the multiply layer style on photoshop.
I added more.
Aha, thx so you just put the layer over the wii u and multiply it and remove the parts where you don't want the image to be on? Okay!
Anyway, try using a tool that let's you stretch the image so that you can rotate it according to gamepad. Cause the text is like facing us while the gamepad is facing to the left.