It is possible to learn and study everything in a (home) simulator except for hand-flying.
Operating an aircraft is (simplified) only about pressing the right switches at the right time and monitoring the aircraft data.
Richard Russel probably didn't do the latter, because the probability that something does not work is low firstly and secondly it wasn't his goal to take care of the plane.
So, it's indeed easily possible to learn how to make this aircraft ready for takeoff, especially if your goal is just to get the engines running. The hand-flying part is something else. But yeah, nobody says what he did was good flying. It sufficed for what he has done.
Also note: He has just done the very basics to get the plane up and fly it. In his conversation with ATC, he asks about how to pressurize the plane and how to operate the autopilot, so he lacks some "deeper" understanding and knowledge of the aircraft. In the background of his transmissions, there also is the master warning audible sometimes.
To summarize: Yes, a home simulator completely suffices for what Richard Russel wanted to accomplish.