Stressful bedtime - need a new routine perhaps?

We cut out our 2 year olds bedtime bottles a month or more ago. Since then, we are finding it so hard to get her to calm down ready for bed, and more often than not, we have a lot of screaming, yelling out for mum or dad and just generally playing up for an hour or more past her actual bedtime.

She's dropped her day sleep, which I can deal with, but it hasn't made bedtime any easier! At 5pm ish she seems really tired and then all of a sudden she gets a new lease of life, which I think is being overtired.

Any ideas? We've never had a really strict routine when it comes to evenings because she's always gone to bed really easily but with a 10 week old bubba as well, this is doing my head in :(

Start a new constant bed routine..
Dinner, bath, cup of milk, teeth, book etc...

When I weaned DD1 at 18 months we replaced it with something, that something was a new book that we read every singe night for probably a year.

We're having very similar issues here, so it could be an age thing. although DS is still having a short day sleep and I haven't been brave enough to cut the bottle out yet. He is taking well over an hour some nights to calm down enough and stay in bed. I don't have any tips, but at the moment, one of us is sitting by his door so he can see us and then lying him down every time he gets out of bed. It still took an hour tonight but I'm hoping this might work in the long run.

My tip is to be consistent with the routine and flexible with the times. DD2 was taking over an hour to get to sleep until I moved her bedtime to later and now she's out within 10 mins.