1) Create a new Eclipse project
2) Import the .xsd into the project from file system
2a)
2b)
3) Select the .xsd and create an EMF Generator Model (under "Other")
3a)
3b)
4) Select the model and export to UML
4a)
4b)
5) Select UML model and create new Papyrus model
6) Create a new class diagram and drag-and-drop the wanted elements onto it. Done!