INSTRUCTIONS:NOTE THE STL IS PROBABLY USELESS TO YOU - unless you happen to have a Dell Inspiron 531 mainboard. You almost certainly will need to work from the SCAD file. I only uploaded the STL so that the site would show a representative image.Download the OpenSCAD file. Edit the "holes()" module by adding all of the I/O types that you have on your system, measuring from the lower left of the case opening to the lower/left side of each connector. For instance, my VGA connector is 41mm from the left of the hole to the left of the connector, and 5mm from the bottom of the hole to the bottom of the connector, so I add this:translate([41,5,0])vga();Do all of the connector holes, print, insert into the case from the inside. There are little bumps along the edge which you need to snap into place. If some of them break off it's not a big deal as the mainboard will actually hold the plate in place just fine, the bumps are just for convenience. After inserting the plate, install the mainboard and build up the rest of the system.