If I got a phone from an estate sale how can I remove the Apple ID

You can't unless you know the person who's Apple ID is on it or when you bought it at the estate sale they gave you the original receipt from when it was purchased from Apple or an Apple Authorized Reseller.

Hi!

You wouldn't be able to. The original owner would need to remove that for you.

Hope this helps,

Richard

You could factory reset the phone but you would need the login information in order to reset it.