Question

Need help with how to go from:
n(1/((2^n)(n!))((2n)!/(n!))
to:
n(2n/(2n^2))(1/((2^(n-1))(n-1)!)((2n-1)!/(n-1)!)((2n-1)!/((2^(n-1))[(n-1)!]^2)