There are several ways to reset your App Store, iTunes or iCloud password, depending on the security verification options enabled on the account. Some options include requesting a password reset link be sent to a registered email address, answering security questions online or verifying an associated phone number.
All of Apple's online purchasing and storage services, such as the App Store, iTunes and iCloud, are controlled by one account known as an Apple ID. If you need to reset the password for your Apple ID, the first thing to do is visit Apple's password reset website iForgot.Apple.com. From this page, a user can choose from three different password recovery methods, as of March 2015.
To reset a password via email, you first enter the Apple ID and then enter the email address associated with the account. This sends a password recovery email to that account that contains a link that allows the user to choose a new password for the account.
To reset a password via security questions, again first enter the relevent Apple ID then choose the security questions option. This displays the user's security questions, and once answered, the password can be reset. Resetting a password via two-step verification involves entering in a special code sent to an associated device if this option is enabled.