I'm unable to change my first and last name

You cannot change your first and last name because your account (personal organisation identified with the "Me" badge in the Organisations section of your account) cannot be transferred to another person. While you can transfer the ownership of your products (with the exception of your SSL certificates), you cannot transfer the ownership of your personal account itself (for legal reasons).
Therefore, please refer to the change of ownership process in our documentation.
The only exception is if you are changing your first or last name due to a change in civil status or an administrative procedure: in that case, please submit your request via the form "article 16" ; we may ask you to provide the necessary supporting documents.

Changing the owner of a domain name