The only user who's demonstrated merge rights on the repo is the repo's Eclipse Foundation project lead, Laurent Spaggiari: https://projects.eclipse.org/content/laurent-spaggiari-proje...
Who's the only listed contributor on the repo: https://github.com/polarsys/b612/blob/master/CONTRIBUTORS.tx...
And who's been publicly inactive on GitHub since the repo's last merge in March 2019: https://github.com/LaurentSpaggiari?tab=overview&from=2019-0...
I don't think any amount of tooling knowledge could facilitate a contribution at this point. It's a dead project. The best anyone could do is apply the steps in issue #24 to a fork and start promoting it.