If you want to modify the registrant details of a TLD domain (all extensions except .es), you can do it easily from the control panel of cdmon. Modifying the name and/or email of the domain registrant must be validated by the current registrant email account, and if the email account is also modified, it must be validated by both the current and the new account. This validation is done through a link sent to the account or to both accounts. 

To make the modification, access the domain control panel by clicking on the DOMAIN option.  

• Form for individuals

• Form for organizations 

Click on the Save all contacts option and you will automatically receive an email in the current registrant account to validate the changes. If you modify the email account, you will receive an email in both the current and the new account, and both accounts must validate the change.