\( y=\left(x^{2}-4 x+1\right)^{5} \)

Step 1 ：\(y=(x^{2}-4x+1)^{5}\)

Step 2 ：\(y' = 5(x^{2}-4x+1)^{4}(2x-4)\)

Step 3 ：\(y'' = 20(x^{2}-4x+1)^{3}(2x-4)^{2} + 40(x^{2}-4x+1)^{4}\)