How to make a will

Sir, 

I want to make my Will in favour of my wife for 100% share in favour of her. I have seen in format of Will and find about appointment of an Executor who could execute my Will after my death. It is not understood to me if I make only one person as  beneficiary even then I need to appiont an Executor or is it not necessary or the beneficiary himself can be appointed as an Exector of Will to get it executed it in his favour by himself. Please advise.