You can read the publications from the IRS, and/or use consumer resources, such as google this:

roth ira excess contribution removal

Removal before the due date of the return is how you avoid penalties; it's as if that never happened. That isn't going to avoid tax on earnings when earnings were made on the excess. And you might be thinking of how you can designate excess contribution as applicable to the upcoming (current) tax year, but earnings are not contributions; you cannot withdraw excess contribution and leave earnings as if they are the contribution.