1. **Open Settings**: Tap on the "Settings" app on your iPhone's home screen.
2. **Go to Face ID & Passcode or Touch ID & Passcode**: Depending on your iPhone model and settings, you'll find either "Face ID & Passcode" or "Touch ID & Passcode." Tap on it.
3. **Enter your current passcode**: If prompted, enter your current passcode to proceed.
4. **Change Passcode**: Scroll down and tap on "Change Passcode" or "Change Passcode" option. You may need to enter your current passcode again to confirm.
5. **Enter new passcode**: Next, enter your new passcode twice to set it. Your new passcode must be at least six digits long, but you can also use a custom alphanumeric code or a 4-digit code if you prefer.
6. **Confirm**: After entering your new passcode, you'll be prompted to enter it again to confirm.
7. **Finish**: Once you've confirmed your new passcode, it will be set, and you'll return to the Passcode settings screen.
That's it! You've successfully changed your iPhone passcode. Make sure to remember your new passcode or store it securely. You'll need to use this new passcode to unlock your iPhone and access your data.