He's terrible!

Ease him in you say? Well try setting a good mood of relaxation, and I would not say get horny with him just set a good mood. And if that does not work like try to be alone with him, and then try kissing, umm most guys don't do well with having ppl watch for their first time or what not.. ya just try to be like there and comfort him into it and ask him if he likes it and what gets him uncomfortable and stuff like that,, also use common sense and I can see that you have a lot of but try doing that .. and I can tell that you are annoyed with this but you like the guy and you want it to work otherwise I would not think that you would be asking for help with this and that is good that you are committed to him also try to ask his help with it!!! have fun good luck!!

If he thinks that he's already a great kisser, he might resist change. But, since you're probably both under 18, chances are good that neither of you are experienced enough to feel that way.

The best method is to demonstrate to him how you would like to be kissed. Sit him down, tell him to relax his lips, and say, "Could you try kissing me like this?" Then plant one on him.

Practice makes perfect.

Well maybe he is just inexperienced in kissing, things will get right in time, don't tell him you think his kissing sucks because he will feel bad and he will be to afraid to try. show him how you like it, tell him how you like it. and eventually he will get the hang of it.

Just show him how its done you don't have to be making it obvious that your trying to change the way he kisses just guide him !! ive had guys like this and after awhile they get really really good !!

Practice makes perfect. Don't tell him that he's terrible. Show him, how you think it should be done, like a suggestion.

Unless it's the torpedo, then he's probably not relaxed enough to be giving a good kiss, so give him time, and try something sensual instead of kissing. Maybe a massage?