Gather all your cut materials and the glue you'll need. I used Gorilla Wood Glue which works well, but any wood glue should work(you should be able to use hot glue as well). You will also need any weights to help hold the pieces as they dry. I used metal sockets which work quite well.

First, glue the pieces together as shown in the images above. Be sure the glue is dry before moving on to the next step

Apply the glue to both sides as seen in the first image, also apply glue to the seam where the ends connect. You will need many weights for this step, also find something that will snuggly fit inside the box to hold the weights above it.

This is by far the hardest step. Just make sure to be gentle when bending the ends over, because they can crack if done too aggressively. It is extremally important to make sure the glue is completely dry before removing the weights.

Next, glue the back cap on and after that, glue the 1/16" wood piece inside the box. Once you've done that, you've competed the exterior box. Now we can move on to the sliding shelf

This step pretty straight forward, just fit the pieces together since they only fit one way. The most important part is to align the holes where the handle bolts go.

I ran a seam of hot glue inside the box as seen in the last image. That's optional, I did it because I wanted the extra rigidity.

Lastly, super glue the magnets inside the holes (make sure they are oriented correctly) and screw on the handles. 

If you have any suggestions, comment them and I'll see if I can make the necessary design changes. If you made it this far, I'd appreciate it if you commented a photo of your finished product.