Do Modifications and create Pull Request

A Pull Request is a request for merging code that we have modified, with the main code

1. First we update the remote upstream to have the last code:$ git fetch upstream
2. We generate a new branch for the modification ([branch mod]) from upstream/[origin branch]: $ git checkout -b [branch mod] upstream/[origin branch]
3. We perform the code modifications
4. We make a commit, for example: $ git commit -am 'FIX partner onchange'
5. We upload the new branch: $ git push origin [branch mod]
6. From the Github web, we create the Pull Request