How to Change your Nickname in Pokemon GO on Apple iOS
The main condition for being able to change your name within the game is by updating to version 1.3.0.
Step 1. Open the Pokemon Go Map view.
Step 2. Tap the PokeBall icon, available centered, in the bottom part of the screen.
Step 3. Next, hit the Settings icon available in the top-right corner of the iPhone’s display.
Step 4. Tap the Change Nickname label.
Step 5. Confirm that you want to tweak your name by selecting Yes, when you’re prompted.
Step 6. Type your new Nickname and hit OK.
Note: If your new username isn’t free, you’ll be asked to tweak it again.