This guy likes me and he knows I don't feel the same way but he wants to be friends but I don't. How do I say that in a nice way.

Just be honest. Just tell him that you know his true intentions, and you're really genuinely not interested, although flattered.

https://www.askmehelpdesk.com/teens/guy-likes-me-more-than-like-him-554724.html

Same guy?

If this is the same guy as Talaniman asked then could you tell us how old you are and how old this guy is? If he is particularly older than you then this harassment HAS to stop, you may need to involve a parent or police.

It is but I told I didn't want to be friends and it's good now