i have two apple ids but im trying to delete one. but the one im tryin to delete has my apple music how can i change it to my other apple id?

I have two Apple ids. And I been trying to delete one of them. But the one I’m trying to delete has my Apple Music and I don’t want to delete everything. How can I change it to the other one? And if I can how can I delete it if it won’t let me even log into it?