How to wean from bottle?

My son is 2 years old we just took the bottle away for night time (yes I know it took forever) we are a week in without a bedtime bottle and it’s taking him literally hours to fall asleep. He doesn’t cry just talks away. His bedtime is usually 8:30-9 but the past couple nights he’s been not falling asleep until close to midnight. Once he’s asleep he will sleep for a good solid 12 hours and he will have a 2-3 hour afternoon nap. Should I cut back his nap time to see if that will help him fall asleep better at night? It’s just weird this started as soon as the bottle was gone.