John Stamos filmed scenes with Jesse and Stavros in the same frame as Jesse first. Then Stamos would go back and reshoot the same scenes as Stavros in front of a green screen. During closeup shots and a fight scene, a double was used to fill in for whichever character did not show his face to the camera.
Stavros' name came from simply taking John Stamos' last name and replacing the "m" with a "v" and an "r."
John Stamos appears in a double role as both Jesse and Stavros.
John Stamos' appearance as Stavros was achieved using hair gel, a fake mole, a fake nose, possibly a fake mustache, sometimes a green screen, and sometimes a double.