TypeError: fit() missing 1 required positional argument: 'X'

Question

The code i tried is-

X = dataset.iloc[:,:].values
from sklearn.preprocessing import Imputer
imputer = Imputer(missing_values = 'Nan', strategy = 'mean', axis = 0)
imputer = Imputer.fit(X[:,2:52])
X[:,2:52] = imputer.transform(X[:,2:52])

The error i am getting is - TypeError: fit() missing 1 required positional argument: 'X'