S.H.
Do NOT feel pressure about it... ALL Pediatricians tell parents this, about the bottle.
Me, I just went according to my son. Yes, at 18 months old, they CANNOT understand our "adult" logic about it, nor excuses for it.
My son weaned from the bottle around 2 years old... I would only give it to him if he asked, and if he "remembered" about his bottle. I only brought it out for sleep times. If he woke and wanted milk/bottle, I did.
But on his own, my son just lessened his "need" of it. Then my son would accept it with water in it... for me, I found that my son just liked to 'twiddle' the nipple of the bottle... it is a soothing thing for him, and he'd 'cuddle' the bottle. But he has his lovey too ....so then gradually the bottle became less and less. My son just likes to hold something when he sleeps. Then I just started to tell him "put away" now (his bottle) and he'd go and put it on the counter himself.
So I just took a laid-back approach to it. I told my Pediatrician I would do it in MY own time, and my son's. No biggie.
Don't feel 'intimidated' by it, and your Pediatrician's orders. They all tell parents this.
In other cultures, kids have their bottle well into toddler hood. It's not a big deal for them.
The concern would be tooth rot. So, I'd use "Spiffies" tooth wipes on my son. http://www.spiffies.com/ And it's REALLY great.
Each Mom is different... I don't feel its such a big deal.
It's a GRADUAL thing, to wean from bottle or breast. They both have 'nipples' and so a child naturally likes it.
All the best,
Susan