Friend zoned is where you try to start courting a lady that catches your eye, but instead of agreeing to your proposal, she says "Awww, I'd rather us just be friends" or worse.. "I see you more as a brother".
Blake, I think the best way to let her know is with either: A grand gesture or with honesty and openness. Show her your vulnerable side whilst you tell her but at the same time remaining brave and not nervous.
It is probably best to have some kind of relationship with the crush in the first place such as a friendship, then you can maybe touch their arm in a flirtatious way.