Mr F says: Apply the definition of each and then do the necessary integrations. If you're stuck with the integrations, please say what you've done and where you get stuck. Try to learn some latex to better type the complicated mathematical expressions that occur.
Alternatively, you could use the moment generating function. This makes life a bit easier.
and thus derive E [((y - µ)/σ )3 ] and E [((y - µ)/σ )4 ]- 3 in term of µ and σ2(square)