How can i open an old Dell Optiplex computer case?

I found an old Dell Optiplex computer tower that lays horizontally and the monitor sits on top of, but it doesnt have any screws to remove so that I can open it up and add a new hard drive. The lid wont come off and I was wondering if anyone knew how to open it.How can i open an old Dell Optiplex computer case?
The chassis is tool-less, you need to press buttons on both the top and the underside of the case to open it.





Hope this helps.





Good Luck.How can i open an old Dell Optiplex computer case?
On the back of the computer there should be a spot where a padlock would go. Slide it so that the holes do not line up. This unlocks the case. There should be an additional button on the front. When you push it the sides/top should come off.





I had a fight with one of those not to long ago myself.





If all else fails you could always use a sledge hammer or run it over with your car. :-)