When Claudius sends hamlet to England what do the papers carries advise do?

Claudius sends Hamlet to England with a letter to the King of England requesting Hamlet's immediate execution. The letter actually instructs the King to kill Hamlet.

Hamlet, however, discovers the letter and alters it, changing the instructions to have Rosencrantz and Guildenstern executed instead. This cunning move saves his own life and sets in motion a chain of events that leads to further tragedy.