I'm meant to be gone for a bit, but I just saw this and had to take a gander.
First off, don't just go up to her and be like "Hey, I like you", they tell you to be directly honest with them but it's not always the way to go, talk to them for a while, drop a few hints that you like them, without saying it, see how they react to it, if they laugh it off, bad luck dude, but if they respond in a way that's similar to what you're saying or feeling, you may be in luck.
Another good way is to not interact with them in a flirty or "Hey, I like you" way, seeing as you may seem desperate or nervous and that'd be a complete turnoff for a girl, maybe drop them a DM or a message, seeing as you'll be more confident not speaking to them face to face, it seems bad but it's a good way, message them for a while and get to grips with what they're like and if you really have a chance.
If they don't respond to a message, don't keep responding, they're not interested, for example:
"Hey"
"Hey"
"Did you get that last message?"
"Hello?"
You'll seem desperate, if they don't respond, leave it at that.
I've been in a relationship for a while and I'm happier than I've ever been in relationship terms, try the messaging, if it don't work, then whatever.