It is customary after some time to get bored at one’s own case, and to want it to look cool in one way or the other. One (also) useful way to modify it is to make a panel transparent, so you can see inside, and check if all fans are working, or see what’s the model no. of an HW component without using a screwdriver. This naturally applies only to tower (mini-midi-full) cases, and the guide itself uses some techniques which may not be appliable to every model; I decided it was much easier to exchange a whole panel with plexiglas, instead of sawing off a square from the original aluminium, possibily damaging it and my own fingers, and below you can see what I was able to make.
My case structure had some incisions to let some stirrups on the alumium panel to make friction and stay stable.
First, you need to provide yourself with the necessary material: a plexiglas panel, the same size of the aluminium panel you want to replace (I used a 2mm thick one), and then both a instrument to make holes in plexiglas without fracturing it (I used a screwdriver-shaped solderer to melt where I needed), and a series of straight thin metal stirrups you can easily bend.
Put the plexiglas panel in place, and with a marker draw on it the side of the holes where the grip should occur, then about 5mm ahead of it make a vertical hole with the solderer. I decided to use only the first and last holes on the upper and lower side of the panel, to reduce the amount of work, and the probability of bad alignment of all the stirrups. In this phase you should also write with a marker on the plexiglas "OUTSIDE", so you can easily find the orientation of the plexiglas against the case.
Bend the gripping side of the stirrup to reproduce the U-shaped hook on the aluminium panel, insert it in the hole, then bend again the long straight side to fix the stirrup on the plexiglas.
Try to adapt the just completed panel, which will almost for sure not be perfect, but adjusting the bending of the stirrups, or forcing them in the holes will get it to work.