Go to Settings > iCloud, if you have already signed in, tap on the Apple ID > Password & Security > Change Password. And type the new password that you want in the blank. If you haven't sign in the iCloud account, go to Settings> iCloud, click "Forgot Apple ID or Password" and type in your Apple ID.How do I recover my forgotten Apple ID password?
Click your account information at the top of the screen. Choose Password & Security. Tap Change Password to recover your Apple ID password. If you forgot Apple ID password, recovering your login information is a fast, straightforward process.What to do if I Forgot my Apple ID?
What to Do if Forgetting Apple ID. Go to your Apple ID account page and click Forgot Apple ID or password When you're asked to enter your Apple ID, click Forgot Apple ID. Enter your first name, last name, and email address. If you enter the wrong email address, you can try again with a different one.