How do I change trusted numbers on my Apple Account?

Apple has these instructions in the support document Use two-factor authentication for your Apple Account on iPhone - Apple Support

Add or remove a trusted phone number

Adding trusted phone numbers can be useful if you want to use two-factor authentication but don’t have access to the phone number you added when you turned it on.

1. Go to Settings  > [your name] > Sign-In & Security.
2. Tap Two-Factor Authentication, tap Edit (above the list of trusted phone numbers), then enter your device passcode when prompted.
3. Do one of the following:

• • Add a number: Tap Add a Trusted Phone Number, then enter the phone number.
  • Remove a number: Tap  next to the phone number.

4.When you’re finished making changes, tap Done.

Trusted phone numbers don’t automatically receive verification codes. If you can’t access any trusted devices when setting up a new device for two-factor authentication, tap “Didn’t get a verification code?” on the new device, then choose one of your trusted phone numbers to receive the verification code.