As you see in the below screenshot my Aadhaar has not been updated in the UAN Portal.To update Aadhaar follow the below steps
Steps to Update Aadhaar
Step 1: Go to Manage —> Modify Basic details
Step 2: Modify Basic details would be displayed as shown below, Enter your Aadhaar No, Date of Birth and then click on Update
Step 3: Once you clicked on Update , it will display a popup as shown, Click on Yes in the Popup
Step 4: Changes requested successfully message would be displayed at the top as shown below
Step 5: You have to contact your Employer to approve Aadhaar, once your Employer approves Aadhaar, PF Office will take somewhere between 0-15 working days to approve your Aadhaar