What kind of answer are you expecting to a question that's effectively "how do I generate text that conforms to some format Foo"? Not only that, I have to wonder, is generating a text file really the best way? Probably generating the model instance and serializing that is the better way. Why did you decide on this approach? What have you done so far to answer your own questions?
Ideal would seem a model to model transformation technology (or just Java code) to create an instance of the SYSML model and then serialize it. I think Papyrus support for SYSML so I suppose they have an Ecore model for it. But note that this is the EMF forum, not the M2T, M2M, nor Papyrus forum.
I'm not sure the point in deleting a bunch of your messages, but it's poor behavior. Answering questions takes effort but the answers can be useful for other people. That's no longer the case if you delete the question.