To create an upstream fork of the repository in GitHub, click "Fork" in the top right button on the main page of the [Plume repository](https://github.com/Plume-org/Plume). Now, in the command line, set another remote for the repository by running the following command, replacing `myname` with the name under which you forked the repo. You can use another name besides `upstream` if you prefer. Using [SSH](https://help.github.com/articles/connecting-to-github-with-ssh/) is recommended.
Now, make any changes to the code you want. After committing your changes, push to the upstream fork. Once your changes are made, visit the GitHub page for your fork and select "New pull request". Add descriptive text, any issue numbers using hashtags to reference the issue number, screenshots of your changes if relevant, a description of how you tested your changes, and any other information that will help the project maintainers be able to quickly accept your pull requests.
The project maintainers may suggest further changes to improve the pull request even more. After implementing this locally, you can push to your upstream fork again and the changes will immediately show up in the pull request after pushing. Once all the suggested changes are made, the pull request may be accepted. Thanks for contributing.