Although some words like re-cover (cover again) and re-create (create again) need a hyphen for clarification (recover without the hyphen would mean regain and recreate would be play) Restaple is clearly to staple again and needs no hyphen. What is the purpose of using a hyphen in words like re-cover and re-create?
1) To clarify the meaning of the word
2) To indicate repetition of the action
3) To emphasize the action
4) To make the word sound more formal