I need advice!

Okay so I have an almost 15 month old daughter who sleeps in bed with us still but I desperately need her to go to her own room now that I’m having another baby in two months. I don’t know the best way to go about this without making her extremely upset, I mean even if it does make her upset I don’t have a choice, she can’t be in bed with us any longer. I want to go the smoothest way possible but I just don’t know. Anyone who sleep trained somewhat late like me and how did you do it?