Hi R...
Don't worry he will get it, He won't want to wear pull ups for ever.. I have two boys 5yr old and a 4yr old, I started potty training them the day they started walking no joke. This is what I did and you could try it with him.. Both of my boys was fully trained on there 2nd birthday, My oldest was better then my youngest (all children are diffrent, RIGHT?). All I did was every time I went to the potty they went with me. I sat them down next to me on there little potty, and talked to them telling them how much better it was to go peepee in the potty. After I did that a few times I let them watch daddy go potty, they liked the idea of standing up to go potty, To help them like it more I put some Cheerio's in the potty so they could aim at them, every time they went potty poopoo or peepee we came out singing a song that I made up and telling them how proud I was. I acted really silly and made a party out of it dancing,singing,claping jumping up and down around the house.. It was fun, thats what you have to do make it fun for them. Good luck with it.. I am looking forward to read how things are going once you had a little time to work with him more..
Ps.. while doing all of this I did put them in big boy underwear and I did the stickers.
M.