You need to generate a new CSR with the new contact details and apply for a reissue of the certificate. Once the certificate is reissued, you will be sent an email with a new certificate. Install the newly issued certificate on your server.
Note! Please keep in mind that the company details for OV/EV certificates can be changed during reissue only within 45 days since the certificate issuance. If you try to change the company details for the certificate that is issued more than 45 days ago, the reissue process will most likely result in an error.