I did it the same way my Mother did it with me. I put a bottle in front of him, and a sippy cup. I sat in front of him and drank from the sippy cup. I picked up the bottle and tossed it in the trash from where I sat. Then I just looked at him and waited. He picked up the cup and started drinking from it. End of story.

If he's getting occupational therapy, speak with his therapist and see what he/she recommends.

I used a sip cup for my son with the soft top like a bottle.It worked for him verse the hard top felling.He's still attached now but his doctor &therapist suggested it was his comfort so we are still working on transitioning off the cup.

We still give him a bottle at in the morning, naps, and nighttime. I find it soothes him, and he doesn't eat much else. During the day I leave his sippy cups out so he always knows its close by. It's worked for us. I also got cups with animals on it, because those are his favorite.

When I first started teaching I had a child who still took a bottle. We slowly started cutting the nipple off. We began by just making the hole bigger and bigger until the nipple part started getting smaller. Eventually it was no longer rewarding and he moved to sippy cups. You have to be careful when you do this though because the edges can become sharp when you cut the nipple. We did this very slowly to allow for plenty of transition time.