Expired domains are retained during the grace period for the previous registrant to renew. During that time, only the previous registrant has access to renew that name. To renew your domain, visit myCP -> Domains (in the left side bar menu) -> Domain List -> [your domain] Select the domain(s) you wish to renew and then push the green “Renew Selected Domains button” Follow the prompts to completion.
If you have any issues or troubles renewing your domain submit a support ticket requesting to renew the domain and the hostmaster will manually renew the domain for you.