Need help getting 3yr old off the bottle

Hi all my 3yr old son Thomas is extremely reluctant to give up his bottle. I try to take it away but as i still have a little one on a bottle im finding it hard. Ive tried telling him that only babies have bottles and that he is a big boy and has his cup but he says he is a baby and needs a bottle. Im a little lost on what to do as he requires up to 3 bottles to go to sleep at night and frankley im shattered by the time he is down. His brother who is 21 months has one bottle and is out like a light. I need help badly im am wanting to settle down in a more suitable routine.

With my daughter we chose a special big girl cup at the supermarket but she was only allowed to use it when she stopped having her bottles.
We left it on the bench all ready to go and let her tell us she wanted that instead of the bottles.
We put all the bottles in a bag and sent them away for new babies who needed them and when she asked for them were able to remind her they were gone.

I guess it is not so straightforward for you, having the younger one still on the bottle but maybe you could make a big deal about him being big enough to have the special new cup and little brother is not big enough yet so can't have it?

Good luck!

Another thought is that you could get your younger one off the bottle too..... special different cups for both kids. Make it a big deal, talk about it lots, send all the bottles away so that it's just not an option.