How and When did you start going from formula to milk?

So here is a small background of my babies feeding.

For 5 months she was feed breastmilk but because my supply was lowering we had start formula(similac sensitive)

Now she is still on similac but I have tried two milks

1 whole milk(which she doesn’t like very much)

2 lactose milk(which she loves)

She is now 11 months old and will be 1 year in July. How can I make this transition easier for her and her little body without her having to hate milk or anything going wrong idk I’m a first time mom!? So please help and let me know thanks!! ❤️❤️