If Synthclipse perspective is not already opened, from the main menu choose Window -> Perspective -> Open Perspective -> Other.... In the Open Perspective Dialog choose Synthclipse and press the OK button.
From the main menu choose File -> New -> Synthclipse Project. Name your project and click the Finish button.
From the main menu choose Synthclipse -> Fragx Examples... or Synthclipse -> JSX Examples.... Select some examples, choose your destination folder and press the Finish button.
From the Project Explorer View open some Fragx shader or JSX script and run it by clicking on the black "play" icon in the main toolbar or by pressing Shift + F12.
If there are no errors in the Console View you should see output of the shader/script in the Viewport View.