When using your key file with a Windows 10 or 11 host you similarly put your key into a text file called authorized_keys in a hidden .ssh folder in your user folder. For more security, your authorized ...

At this point, your new public key should be on your EC2 instance in the authorized_keys file, and all you have to do is remove the old one.

An example above of in-place sed edits to remove a key is one option worthy of study, and preparatory sed processing for cleanup of authorized_keys might involve the /^$/d pattern to remove blank ...