What is mechanism for amending registration certificate under GST law?

What is the mechanism for amending the registration certificate under the goods and services tax (GST) law? 

If there is change in any of the particulars furnished in the application for registration, a person is required to file an application within 15 days. The amendment is required to be filed online on the GST portal. 

Upon submission of the amendment application, the proper officer may approve or reject amendments in the registration particulars within 15 working days from the date of receipt. Permission of the officer for making amendments will be required for those in core fields of information. For the other