If life on Earth was seeded by extremophiles from Mars via a meteorite, how would that happen?

Mars rocks hit Earth with surprising frequency, even today. You could say that the inner solar system "geologically communicates". Remember Mars does not have a very strong magnetic field so it gets hit by meteorites all the time (of various sizes) and Martian dust and rocks gets jettisoned up into the weak atmosphere and into the solar system. Sometimes the debris finds its way to Earth! We know that this would have happened at a much higher frequency in the early solar system because the early solar system was so chaotic and meteorites collided with planets at a very high frequency. We also know that simple prokaryotes can exist almost anywhere... even on meteorites and asteroids.

Of course we don't know whether abiogenesis first started on Mars and then early life was transferred to Earth. It is still just a hypothesis and not necessarily more likely than the alternatives that abiogenesis just started on Earth, or abiogenesis started on both Mars and Earth simultaneously!