If you have submitted you form, then you can't edit it. Now if you haven't submitted then you should do the changes and then save the form by clicking on the option available at the end of the page. After all your changes you can submit the form and then can pay the fees of Rs.100 and the application process is done.

To know more about SSC CGL, visit the link below:

https://competition.careers360.com/exams/ssc-cgl

I hope this answer helps. All the very best for your future endeavors!