As I commented, for a github thing, you might make a pull request. Don't change the owner name but add your own name as contributor (and update the copyright years). YMMV. And don't change the license (e.g. to GPLv3+) without permission from the original author (unless you are sure that your license is upward compatible with his one, and even then you'll better discuss that with him). But I am not a lawyer!
The original author has then the ability to incorporate your changes, and the github platform offers an easy way to do that for him (or her) if he / she wants to, if your changes are organized as a pull request.
In general, you'll rather try to cooperate & interact with the original free software project authors and community. Forking a project is often frowned upon.