Hum, you don't need to do this. If you put a compact face down on a bed, remove the screws, and then sort of "snatch" at the sides with flat palms, the pressure pulse inside from your hands comming together combined with the resistance to acceleration of the main mass of the computer means the case releases with no chance of marks.
You only need to lift it an inch or two.
It sounds worse than it is? But basically it doesn't put any metal against the plastic.
If I didn't want to do that, you could always use a plastic spudger.