Step 1: YOU DON'T.
You're an independent human who needs no other human to validate your existence. I get it, you like them and all you want is for them to return the feeling.
You think your crush liking you back will fix all your problems? Well do I have news for you...it won't. You are the only person who can fix your problems because you are the only one who controls how your life goes.
Like John Green wrote, "what a treacherous thing to believe a person is more than a person". Although your crush may seem like a worship-worthy figure, they most definitely aren't. Everyone has flaws, and everyone makes mistakes because we're only human, so believing this person is perfect is irrational.
You need to stop fantasizing about this person and realize that you don't need them to like you back. In fact, if you're so desperate for them to like you back why don't you try putting that motivation into loving yourself? All the wasted time and devotion you're putting into your crush can be used to better yourself.
The world can be a cruel place, but having your own back and having full confidence in yourself can make living so much simpler. Stop wasting time thinking about how to get that person to like you back and work on improving yourself. Put all your time and energy into something that you can benefit from.
They may have the best smile, the softest hair, or the kindest eyes, but they are just a person like yourself. Having them like you back is no victory. Sure it would be great to have your crush like you back, but you don't need them to. They do not validate who you are as a person, and they should not have the power to make you feel bad about yourself.
You are strong, beautiful, courageous, and worth so much more than what someone else thinks of you. If your crush can't see how great you are before your efforts in getting them to like you, then they don't deserve you.
Spend time being the best version of yourself and you will attract the right people. The right people won't need proof of how great you are because they'll already know. Trust me, I know having your crush like you back would be the best feeling ever, but hear me out when I say it's not worth it. Your time is precious, and wasting it on an unworthy person is not nearly as satisfying as it would be spending all that time on yourself.