Opening the Dimension 4400

[Jaz1]

Hi all,
I opened my dimension 4400 and installed a PCI adapter; tonight I
tried to open my husand's dimension and when I push the button on the top of the tower the bottom part of the tower is able to push out but the top
seems to be stuck. Should I be pushing another tab? Do these buttons get stuck? I'm afraid to pull too hard and break the plastic at the top. Am I missing something? Any tips?
Thanks.

 

[dopefisher]

Can you unscrew the sides of the case off?

 

[GeekieNick101]

dopefisher I'm guessing Jaz1's system doesnt have any screws, most newer dell systems do not. It might be stuck trying closing the entire case again and reopening it. Im guessing theres a tap on the bottom and top and it opens (picture below to explain)