It is not easy, but it is possible. I have had an experience of leaving my body while in a lucid dream. It did not last long, but it did work. If you find yourself having frquent lucid dreams to work with and enough control within that lucidity to try a technique, you can dream of being in your body and then leave it. It is possible to dream of being in your body without waking up. It is something of a balancing act.
When you are dreaming and you are lucid you re in astral plane.Surroundings in lucid dream are astral plane.
The idea from past posts was to stare at something in a lucid dream and you will project.
is it possible To Get into a OBEE/Astral plane from a Lucid Dream ?