Just gotta tell her how you feel, man. Just straight up say "Hey, (name), can we talk? (if yes proceed with...) Well... You know, (name), I've been realizing more and more that I'm getting feelings for you." Straightforward, not going anywhere too fast and not too much at once.
Obviously, if she reciprocates those feelings? Awesome! Talk about it. If not or she says she isn't ready? "That's fine, I just wanted to own up to my own feelings was all. Thanks for hearing me out, (name), I really appreciate it." Then just segue into your usual conversations and leave it at that. Simple. c: