It's going to be tough defending LeBron James, hopefully some effective switching can lead to success.
LeBron James is a matchup nightmare. There isn't any perfect option to defend him without a freakish defender like Kawhi Leonard. It is especially hard to defend LeBron when he runs the pick and roll. The Boston Celtics' pick and roll strategy has been a topic of discussion recently, and will be important against the Cleveland Cavaliers.
This season, the Celtics have switched frequently on LeBron in these situations. James is the focal point of the offense, so it's imperative to limit him however you can.