Since you said he only like you a little bit, i suggest you text him. Because you will not know his reaction that well, but if you guys build up your friendship, he will probably start liking you more, and then you can tell him in person. And hope he says he likes you too, and then you'll have a partner :)
You should tell him face-to-face and not via text. Texting shows that you are shy and not confident about what you want to say. If you tell him face-to-face you will be able to know if he likes your for real or not.