As I designed the parts for the cube I didn't had in mind that I will need to get inside the cube sometimes to uplaod new games or maybe repair something. So I redesigned the top a bit to make it removable.

Thats how I made it :

First I cut a big hole in the existing part. ( ..and four wrong holes in the corners )

Next I cut out a new part and drilled four blind holes ( radius = 8mm depth = 2mm ) in the corners. ( I deleted the photo of the other side and some more by mistake )

Next I glued magnets in the blind holes and glued both parts on the cube that way that the magnets are complete enclosed.

Next I cut out the top and drilled four blind holes in the corners ( same size as at the other part ) . Next I glued magnets in the holes and glued some rocketsticks on the back to fix a bend.

On the cube :

It overlaps 5mm, because the plexiglas for the pixel-area will be 5mm wide.