If for any reason you need to change the email address connected to your Apple ID simply follow the instructions below.
Step 1 > Launch the browser Safari on your iPhone, iPad or Apple Mac.
Step 2 > Go to appleid.apple.com.
Step 3 > Log in using your current account details. Sometimes you will be asked to verify yourself after log in.
Step 4 > Select Edit from the Account section.
Step 5 > Now select Change Email Address under Apple ID.
Step 6 > Now enter your new email address which can not be linked to any other Apple ID and select continue.
Step 7 > You will now receive a verification code on your new email address entered.
Step 8 > To complete the process, simply verify the email address and click on done to save the changes.