How do i end a realtionship with my first boyfriend?

So, i really really really liked this guy, and i asked him out, he said yes and i was overjoyed. he was my first boyfriend. Anyway its been three weeks and i really dont like him anymore. As a friend- yes, but not as a bf. I really dont want to hurt his feelings, but i have know idea how to breakup with him cause hes my first. Any ideas. Please and thank you8 soo much for your advice. xoxo