I would eliminate third base, plant trees in the outfield, and replace all the existing players with hot Amish women.
I would require all new stadiums. And they would all have to be built on lands owned and operated by Native American tribes. They would get the franchises for free, so long as they install slot machines in the bleachers and cigar shops in the restrooms.
To reduce overall player salaries, I would eliminate the center-fielder position. I would replace it with a big jumbotron which would show select splatter/vengeance exploitation films from the late 70's, such as "I Spit on Your Grave" and "Last House on the Left."
I would also reduce the game to 8 innings, and allow the fans to shoot toy arrows, with rubber tips, at the team managers and batboys.