As someone who doesn't like confrontation I used to avoid guys who liked me. I would go out of my way to avoid these guys because I didn't want to tell them I wasn't interested in them. Then I discovered a much easier way to get out of those situations. I TOLD THEM. Avoiding them didn’t work, so I flat out told them I was not interested. Turns out most guys appreciate it when you tell them you're not interested instead of just stringing them along.
Tell him you’re not interested in him “like that.” Sure he’ll be sad/upset, but it’s better to tell him now so you don’t lead him on in the future.
Tell him why you don’t like him
It’s not enough to say, “I don’t like you.” Explain yourself. Do you think your better off as friends or do you like someone else? Let him know.
If a guy keeps asking you to hang out, don’t make up something to get out of it. If he’s into he’s going to keep asking you to hang regardless of your excuses.
Don’t go out with him
If you’re not into a guy don’t keep going out with him. If you continue to go on dates with him he’s going to think you like him.
If you flirt with a guy he’s going to think he still has a shot with you.
If one of the options above doesn’t work stop responding to his texts, calls, Facebook messages, etc. Yes, it’s harsh, but if you’ve already told him you’re not into him and he continues to message you this may be your only choice.