I need to change my iCloud password

If you know the current password.

 Apple ID Password Change.   -  

ASC YouTube for How to reset your Apple ID password

 What to do after you change your Apple ID or password - Apple Support  -   I suggest doing this before you change your Apple ID or password.

If you forgot the Apple ID (iCloud) password, enter the Apple (iCloud) ID, and click Forgot Password. See if you can get a Rescue or Notification email option if necessary. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage  -     

Apple ID – Forgot Password  *      

iCloud uses your Apple ID and password. To change the password, see: Change your Apple ID password - Apple Support

If you only have one Apple ID, your iCloud would be the same ID and password as you used to log into this forum. If you have another and have forgotten the ID or password, see the following:

If you forgot your Apple ID email address or phone number - Apple Support

or

If you forgot your Apple ID password - Apple Support