Very easy. Drive to the Fort Wilderness parking lot - that's called the Outpost. Then board an internal bus. If you want to eat at Trail's End, you will take the bus to Settlement and walk to Trail's End. Then after dinner you will have to go back to the Settlement bus stop to the Meadows bus stop for the movie.
If you want to go somewhere else to eat, then take the bus from the Outpost to the Meadows directly.
I highly recommend an evening at the Fort. Dinner at Trail's End, the Chip n Dale singalong, then skip the movie and hop back onto the bus to go back to the beach by 9:30 and see the Electric Water Pagent at 9:45 and Wishes at 10. They pipe the music onto the beach so you hear the show and see all the fireworks in the sky.