You gotta do this in some sort of romantic way though. If you're just going to watch a film or grab a bite then it's no different to being just normal friends.
My gf told me this after we was together (I was friend zoned for 4 months, but that's another story), that she was sure about the normal friend side of things but what she wasn't sure was the bf/gf side of things, the physical side of things if you get me
But anyway, romantic but not overkill like start singing her love songs. I'm sure you know what you're doing though dan. I look forward to the outcome!