Using Laptop/PC:-- Click on 'My Firstnaukri ' option at the top . It will land you on your Profile page. You will find an EDIT option at the top right corner of Personal Details section .

Using Mobile :-- After logging into your account , click on the tab at the top left corner . Then cilck on 'Ask n Answer ' . Click on 'My Firstnaukri' and follow the same above mentioned steps ( Using Laptop/PC).
Hope this helps :)