I'm busy shutting down a throwaway FB account that I used to sign up to Spotify back in the day.

They don't make it easy.

The process, according to Spotify support, is:

+ Create a new Spotify account

+ Contact Spotify support to migrate playlists etc. across.

+ Cancel my paid subscription on the old account.

+ Create a new paid subscription on the new account.

+ Migrate my family members onto the new account.

This is reminiscent of Microsoft's strategies back in the 90s, to make it incredibly difficult to ship a PC w/o DOS (and later, Windows).