We are sorry to see you leave but your music will always be yours so if your decision is final you can delete your account directly from your Indiefy user account.
All your published songs need to be unpublished from this account before you can deactivate your account. Find out how to take down your music here.
Once all your songs have been taken down, you can deactivate your account directly on the artist page in Indiefy. Go to your logo in the top right corner and click Account Settings > Deactivate User.