The answer on the "how to join" question depends on the particular situation at your institution and the software you use for managing student mobility. Please read below which situation fits for your own institution.

You can also have a look at some instruction videos on how EWP works.

At the launching conference on the 12th and 13th of December 2018 at Ghent University (Belgium), more information was released. You can find presentations and videos from the conference here.