Late edit: That card only draws 19w, so you should be fine with that power supply.
/e This is probably the 1st computer I've seen in 20 years where the CPU and the HDD draw MORE power than the vid card.
/ee All you need to do is remove one of the two plates marked with RED dot (w/e one lines up with the PCI-E x16 slot, and put the vid card IN the slot.There will be a small plastic clip near the front of the vid card, and there should be a screw at the back of the vid card, to attach it to the back of the case.
Then just plug your VGA connector into the VGA port on the vid card and you should be good to go.

You will have to install a driver, but the computer should work, even before you install the driver. Let me know when you get the card, and I can help you with installing the driver.

This post was edited by Ghot on Jan 17 2016 12:36pm