How do you tell a guy that you like him?

Me personally I don't I'm hanging on for a psychic. But I'd recomend telling him, it saves a lot of time I've learn't there really isn't many mind readers out there.

kiss him

If you liked me, I would appreciate you saying," I like you". I appreciate straight-forwardness.

so far I agree with "samharley"! Its better off being straight forward, but only if you know he feels something for you as well!
Try doing that would show you care for him! Things that will get to his heart and then he will turn around and see you in a different way! And NO, don't take your clothes off nor waste your
Money on psychic (95% of them just lie to you)!

think about it over-complicated one...

10 years old and under, you run from him at recess.
Between 11 and 13, you punch him.
Older than that, you take your clothes off.

Not saying that I agree but this seems to be the way it is.

You go up to him and tell him how you feel,it's that simple.

For me, I just went out and told him, that I loved him, and I could tell that he could feel the same way.
Don't turn red from embarrassment or, in some cases, from rejection. Don't be afraid if you really like him and you are tired of hearing he likes you or he doesn't like you from others. Tell him how you feel and accept the answer
Ask his friends whether he likes different girls in your class.
If you have the same classes together at the end of the day, ask for help with your stuff.
If you realize he may like you, slip hints (like cook up a nice conversation on something simple, such as homework in a class. When you walk past him or when talking to him, brush against him "accidentally"!
Further on, you need to give him a look.(Make sure it's not scary by practicing with your friends) Hold the look for about 2 seconds,then look away, then 3 seconds later, repeat that step and then look at him 1 final time to see if he is looking back your way! If he is, make sure you don't look scared even if you are. If you are glad that he's looking your way, you should make SURE that you smile when you notice!
If you're sure he likes you, you can get a friend to tell him (preferably a friend who he has known for a while)
If you have his number, leave him a flirty voice mail!
Start sitting next to him whenever you get the chance try to make something you two can bond over. Don't get too clingy and always sit with him just remember he has his mates and you don't want to annoy him.
Always trust him (but make sure he's trustworthy BEFORE you decide you like him!!). If he says something unbelievable or ridiculous, react by asking questions about what doesn't seem right until you have a reason to trust what he says. Don't react by assuming he's telling a lie or out to hurt you.
Don't try too hard... no guy likes a girl over-trying or desperate. Even if you *Don't always assume that a guy likes you.
If he's a confident guy, you could just write him a note saying, "I'm kinda into you. What do you say?"