Keep wiggling it around. Slant forward, backwards. Try with the hood open and with it closed. You're right, it's simply snagging on something and it will come out with some more judicious wiggling, tipping, etc. As long as you don't bend the main frame or the pop-up section, any small bends below the focus screen will be easy to straighten. There is a triangle of sheet metal on each side, that's all, and even if they bend slightly in removal it's no biggie.
The focus screen is two pieces- a ground glass top piece and a plastic fresnel bottom piece. Make a note on the orientation of the parts, including the grooved side of the fresnel. I mention this because a, the plastic shouldn't have ammonia or such used on it, and b, if you get liquid between the two pieces it will be messy and need to be opened, dried, etc.