You first need to download & print the Application that can be accessed from the official webiste url of cbse given below and thereafter take a printout of the application form.

http://cbse.nic.in/faq/dupform.pdf

Then, fill up all the details in the form carefully.Attach these following documents i.e the School Leaving Certificate, Admission documents .Some fee is required to be paid in order to get the corrections/changes. The fee varies according to whether the name to be corrected is yours or that of your parents .The Board may affect necessary corrections after verification of the Original records of the school and on payment of the prescribed fee.  Now, go to the admission office and submit the form.