How can I change Apple ID password??

https://support.apple.com/en-ca/HT201355

Change your Apple ID password

Follow these steps to change your Apple ID password.

On your iPhone, iPad, iPod touch, or Apple Watch

1. Tap Settings > [your name] > Password & Security.
2. Tap Change Password.
3. 
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5. Enter your current password or device passcode, then enter a new password and confirm the new password. Forgot your password?
6. Tap Change or Change Password.
7. Sign in with your new Apple ID password to access Apple features and services. 

Learn more about how to change your Apple ID and update other account information.

On your Mac

1. Choose Apple menu  > System Preferences, then click Apple ID.
2. Click Password & Security.
3. 
4. 
   
5. Click Change Password. Before you can reset your Apple ID password, you'll be required to enter the password used to unlock your Mac. 

On the web

1. Sign in to appleid.apple.com.
2. In the Sign-In and Security section, click Password.
3. 
4. 
   
5. Enter your current password, then enter a new password and confirm the new password. Forgot your password? 
6. Click Change Password.
7. Sign in with your new Apple ID password to access Apple features and services. 

Learn more about passwords and your Apple ID 

Your Apple ID is the account you use to access Apple services like the App Store, Apple Music, iCloud, iMessage, FaceTime and more.

When you create a new password, keep the following in mind:

• Your new Apple ID password must contain at least eight characters, a number, an uppercase letter, and a lowercase letter. 
• You can't use spaces, the same character three times in a row, your Apple ID, or a password you've used in the last year.

Learn more about password requirements and how to keep your Apple ID secure.