Breast Milk?

So my daughter is turning one soon and I have to go back to work soon when she does I plan to stop BF so here's why I'm confused on to what to do...

Do I just cut her off cold turkey?

What do I give at bedtime to help her sleep? - or during the day when she wants Milk?

How do I start the process to stop?

Sorry I just wanted to add- she eats 3 meals a day plus snacks BUT she wants the Milk to fall asleep she like passes out instantly..

She's been introduced to cows Milk- 2% 2oz-4oz a day since 10 months.

Would be okay to replace the BM with cows milk at sleep times? DD associates milk with sleep.