I suggest starting with the Bitbucket documentation. For example, here is how you would clone a repository to your local machine:
https://confluence.atlassian.com/get-started-with-bitbucket/clone-a-repository-861178563.html
After making changes to your .sas files in the locally cloned repository using EG, here is how you could commit the changes and push them back to Bitbucket:
https://confluence.atlassian.com/get-started-with-bitbucket/push-code-to-bitbucket-861185309.html
Or you could commit the changes directly from within EG (as documented in the paper you referenced), then push using Git command-line (as demonstrated in previous link), or using a Git GUI, such as Git Extensions, SourceTree, etc.
Again, working with cloud-based Git repositories (such as Bitbucket, Github, etc.) in EG is almost identical to any other remote Git repository. You clone it to the client, work out of your locally cloned repository, commit changes to your locally cloned repository, then push the commits back to your remote origin repository (Bitbucket in this case).
Casey
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