We can download e-Aadhaar card from online and when we open downloaded e-Aadhaar it will prompt for password to open it. Earlier postcode is postal code of the city and this is changed now.

aadhaar-password

As per new format password is combination of first four letter and your year of birth, For example your name is kumar and date of birth is 10-10-1986 then password to open PDF is

                           KUMA1986