Break the process down into small sections. I haven't used this method but use pins to mark each layer and then match them up together.
https://www.youtube.com/watch?v=jnke_KzeTI8
I use a straight pin to mark centers and side of each layer. You can also use quilting safety pins as they won't slip out of place. Then I layer the pieces matching the pins.
For your project, mark as above and then add another mark at the halfway points on each quadrant. Match up the layers in sections.