Apple ID is the account which is used to access all the Apple services like the App Store, iMessage, FaceTime, Apple Music, iCloud, and more. A single Apple ID and password is sufficient to sign into all Apple services. The Apple ID can be any email address.

Now, what if you no longer have the access to the email account you provided as Apple ID? Fortunately, there is an option to change the Apple ID only if the existing email address doesn’t end with @icloud.com, @me.com, or @mac.com. Follow the procedure given below to change your existing Apple ID with a new Apple ID.
1. Sign Out From Other Apple Devices
If there are multiple devices where you signed in with your current email address as Apple ID then sign out from all the devices except the one on which you change your email address. You can change your Apple ID from the iOS devices starting from 10.3 or you can change from Apple account page.
2. Enter New Email Address
Visit the page appleid.apple.com. Sign into your account with existing email address and password. Click on Edit in the Accounts section. Click on Change Apple Id under your Apple ID and then enter the new email address.

In case if you choose an iOS device such as iPhone or iPad or iPod for changing the email address then navigate to Settings -> (your name). You will be navigated to Name, phone number, email screen. Tap Edit next to Reachable At.

And then delete your existing email address and Tap on continue. You will be asked security questions for authentication purpose. In case if you forgot your security questions, Apple also provided you with an option of changing the security questions for authentication. You need to go to iforgot.apple.com page for changing security questions.

3. Verification
Apple sends a verification code after providing a new email address. Verify your new email id by entering the verification code in the fields provided. Now, your Apple ID will be changed to new the email address that you provided.
4. Sign In
After the verification process, sign into your other Apple devices with new Apple ID.
Solve your problem with these simple procedure.These steps hardly take 10 minutes of your time.