BOSTON — The Lakers won one of two games at Staples Center to start the NBA Finals. Then they lost two of three on the Boston Celtics’ home court. Now they head home needing to win Game 6 on Tuesday to force a decisive Game 7 on Thursday. It’s not an easy task, but the Lakers haven’t exactly done things the easy way this season. “We have a challenge, obviously, down, 3-2,” Kobe Bryant said. “We let a couple of opportunities slip away. But it is what it is. Now you go home. You’ve got two games at home that you need to win and you pull your boots up and get to work.”