Depending on how you're logged in, you can update your password in your Account Settings. Passwords must be at least 8 characters in length, and contain at least one uppercase character, at least one lowercase character, and at least one number OR a symbol.
Updating Your Password via Web
From the Audiomack home page:
Click your username at the top right corner of the screen
Once there you'll find "Update Password" at the top of the profile forms. Select that and then enter the password and your current password. This will update your password for the website and the app.
Updating Your Password via Mobile App
Tap your profile image at the top right corner of the screen
Tap "Change password"
Enter your current password
Add your new password
Confirm your new password
Tap the orange "Update Password" button at the bottom of the screen to save your changes.