How do i change my password?

If you know your current password then you can change it by logging into your account via the Store > View Account menu option on your computer's iTunes, by tapping on it in Settings > iTunes & App Store on an iOS device and logging into it, or via http://appleid.apple.com.

If you can't remember your current password then try http://iforgot.apple.com

After changing it you may need to log out and back into the account on any iOS devices, and possibly computer's iTunes (Store > Sign Out menu option) and then log back in

Do you know your current password, and if so do you have a rescue email address on your account ? If yes to both then the steps half-way down this page will give you a reset link on your account : http://support.apple.com/kb/HT5312

If you can't remember your password and/or don't have a rescue email address (you won't be able to add one until you can answer your questions) then you will need to contact Support in your country to get the questions reset.

Contacting Apple about account security : http://support.apple.com/kb/HT5699 (they should also be able to reset your password)

When they've been reset (and if you don't already have a rescue email address) you can then use the steps half-way down the HT5312 link above to add a rescue email address for potential future use

If you forget your Apple ID password, follow these steps to reset your password and regain access to the Apple features and services that use Apple ID.

If you know the answers to your security questions

1. Go to My Apple ID (appleid.apple.com).
2. Click "Reset your password."
3. Enter your Apple ID and click Next.
4. Select "Answer security questions" as your authentication method. Click Next.
5. Select the birth date associated with your Apple ID, then click Next to begin answering your security questions.
6. After answering your security questions, you will be asked to enter and confirm your new password. Click Reset Password when done.

If you have access to the email addresses associated with your Apple ID

1. Go to My Apple ID (appleid.apple.com).
2. Click "Reset your password."
3. Enter your Apple ID and click Next.
4. Select "Email authentication" as your authentication method. Click Next.
5. Apple will send a message to the primary email address or verified rescue email address associated with your Apple ID. Open the message and click "Reset Apple ID password".
6. When the My Apple ID page opens, enter and confirm your new password, then click Reset Password.

If you have two-step verification turned on

1. Go to My Apple ID (appleid.apple.com).
2. Click "Reset your password."
3. Enter your Apple ID and click Next.
4. Verify your identity: Enter the Recovery Key you were provided when setting up two-step verification, then choose a trusted device that will receive the verification code from Apple.
5. After entering the verification code, create your new password and click Reset Password.

You can find this instructions from this articles:

http://support.apple.com/kb/HT5787