Checkout this video:
Open Settings on your iPhone, iPad, or iPod touch
1. Open Settings, then tap [your name].
2. If you’re using iOS 10.3 or later, tap Profile. If you’re using iOS 10.2 or earlier, tap iCloud.
3. Tap your current name, then enter the new one that you want to use.
4. Tap Done when you’re finished, then tap Done again to confirm the change.*
Tap your name.
If you need to change your name for any reason, you can do so right from apple id account page
1. Go to appleid.apple.com and sign in.
2. Click “Edit” next to the “Name” field.
3. Enter your new first and last name, then click “Save.”
On your iPhone, iPad, ipod touch
Open the Settings app. Tap your name, then edit it. If you want to change your name, tap Change Name. If you want to change your Apple ID, tap Sign Out, then enter new apple id and password that you want to use.
On your Mac:
Open the Accounts pane of System Preferences and select icloud account Click the “i” button next to “[email protected]” in the Account Details section, then click Edit in the popup menu that appears. Change your first or last name in the appropriate field, then click Done.
Tap the text field, then type your new first and last names.
You can change the name associated with your Apple ID in Settings on your iPhone, iPad, or iPod touch; or in iTunes on your Mac or PC.
On your iPhone, iPad, or iPod touch:
Open the Settings app. Tap [your name]. Tap Edit. If you want to change the name that others see when you share with them, tap the text field next to your name, then type your new first and last names. If you want to change your name that appears when you send email or receive Apple ID communications, tap the text field next to “Phonetic First Name” or “Phonetic Last Name,” then enter your first and last phonetic names. If you see Change Password instead of Edit, it means that you’re signing in with apple id password instead of an iCloud Security Code. To change your password open the Apple ID website.
On your Mac or PC:
Open iTunes and sign in with your Apple ID. From the menu bar at the top of your computer screen or at the top of the iTunes window, choose Account > View My Account. On the Account Information page, scroll to the Settings section and click Edit to the right of Name. If you want to change any other information about yourself such as address and phone number or payment method click Edit to edit them too
Apple makes it easy to change your name if you need to for whatever reason. Whether you’ve recently gotten married or want to go by a nickname, you can update your Apple ID name in a few simple steps.
Here’s how to change your Apple ID name:
1. Open the Settings app on your iPhone or iPad.
2. Tap on your Apple ID profile at the top of the screen. If you’re not signed in, tap Sign In and enter your credentials.
3. Tap on the edit button next to your name (it looks like a pencil).
4. Type in the new first, middle, and last name that you want to use. When you’re done, tap Done in the top right corner of the screen.