Fastest way to convert categorical data with 5 classes to 3 classes (Numpy array)

Question

I have an array of shape(5000,5), where 0 = [1,0,0,0,0] and so one till 4999 = [0,0,0,0,1].

I want to convert this to an array of 3 where [1,0,0,0,0] becomes [1,0,0]