TMS street bike visor?

I have a TMS street bike full face helmet and I need to switch out the visor. But the problem is the manual it came with doesn't say how to and there's only one screw on each side. After removing them on both sides it's still not able to be taken off. I really don't want to break it because I would have to go out and buy a new helmet. Does anyone know how to easily and safely remove it without damage?