You break away the panels with Cross in them by poking them with large screwdriver.  If you decide you need it closed again you need a filler panel.  You cant put them back and they are VERY sharp so don't cut yourself. [URL]    
This computer has three PCI card connectors using slots 1,2 and 4 with slot 3 not used. Slot 1 and 3 have removable blank covers. However slot two and four which have the motherboard connectors have a blank which is not easily removable. It would appear you have to brake the blank panel out of the case, may be using the small cross section, is this correct. Many thanks Adrian.[IMAGE]
Otiplex 3080 tower