How to warm up breast milk?

I’m new to this whole breastfeeding thing cause I just had my baby on the 23rd of this month. So I’m wondering how u warm up breast milk that’s been in the fridge all day?

Cause I’ve heard u just put the bottle in hot water to warm up the milk but idk if that’s a good way or not. (We have a bottle warmer but haven’t figured it out yet)