Citizens who have registered for Aadhaar need not wait too long for their cards to be delivered by post. Instead, they can go online and download the cards by following a simple procedure. Citizens must provide their mobile numbers while enrolling themselves.
To download the Aadhaar letter, it is necessary to have both your enrollment number and date time of your enrollment.
Go here first
Fill in your details enrollment number, date time of enrollment, your name, your Pincode and the captcha code in the respective fields and click on the ‘Submit’ button.
You be next asked to verify if your last 5 digits of your mobile are correct, press yes and then you will receive a One Time Password (OTP) on the same mobile number as a part of verification process. If the displayed mobile number is wrong then press ‘No’ and enter your correct mobile number and press ‘Submit’ button. You will then receive OTP on your mobile number.
Then you are asked to download a PDF file thats your Aadhar card or letter which can be used an original Aadhar card and the OTP you got will be needed to open that file.
Enjoy your Aadhar card is with you now.
If you have to update any information in your card one can go here http://aadhaaruid.org/update-your-aadhaar-details-online/
Similar process of OTP has to be followed.