If you have removed 7 screws then you have removed 3 too many. Your only taking out two and the top and two at the bottom. These are the screws that hold the device together. Take those 4 out and the device then clips apart easily from the front panel. The other 3 screws you have taken out i assume they are holding the mainboard in or something, so put them ones back in.
I actually meant 4, I don't know why I typed 7 but yes I needed that last piece of information from you.
So from the basics down,
1. Pop off the middle back using a card or something as such.
2. Remove the 4 screws
3. Flip the system back to the front and carefully pop off the front plastic.
You can also easily disconnect the 2 traces going from the screen to the back by lifting there little handles up, which are in the back. (You can see them in the above picture)
Thanks for helping!