How to open a Dell Dimension 4600 Tower/Case?

[TripleAAA]

There are a few small screws on the back, but otherwise all the edges of the case are sealed with those pop-rivet type things. The screws don't look like they would open the case. They are near the power supply. Is there something I'm missing?

 

[mechBgon]

There are oval buttons on the top and bottom. Push them in to release them and then lift, the case hinges open.

 

[LiLithTecH]

The Dimension 4600 has a COVER LATCH on the back of the side panel
which needs to be moved downward, then the panel slid back.