How remove a old graphics card from a dell?

Im trying to install a graphics card in my dell and i cant figure out how to take the old one out. I saw videos of how to do it on other computers and it seems that there is a screw in which holds in the card but I cant find it. And there is also some little lever on the PCI-E socket that also holds the card in and is suppose to undo the card if you push it. Does a tell computer have these components? If anyone wants to know I have a dell Dimension E520How remove a old graphics card from a dell?Hello,

Here is exactly how to remove the PCI-E card from you Dell E520.

http://support.dell.com/support/edocs/sy鈥?/a>