I need to remove a phone number under my apple ID

Hi joshua56,

Welcome to the Apple Community

How do I remove a phone number from my apple id

NB: You need at least one trusted phone number listed, in order to verify / access the account.

Apple Support's article: "Two-factor authentication for Apple ID"

says:

"Update your trusted phone number on your Apple ID account page

Go to appleid.apple.com.

Sign in with your Apple ID.

Go to the Security section and click Edit.

If you want to add a phone number, click "Add a Trusted Phone Number" and enter the phone number. 

Choose to verify the number with a text message or automated phone call, and click Continue. 

To remove a trusted phone number, click the X icon next to the phone number you want to remove".

The Complete article: Two-factor authentication for Apple ID - Apple Support

All the best :-)