Please follow the below given steps to reissue Rapid SSL certificate .
1.Login to client area and click on Services , it will open the page My Products & Services.
2.Select the domain on which SSL need to be reissued .
3.It will open the page Managing RapidSSL , then click on Reissue SSL and add CSR .
4.After providing CSR , select the verification method .Email verification and file auth verifications are there .
a. For email verification select one email address from list .Verification email will be send to that email ID , open that mail and click on verification link provided .
b. For file auth verification you have to upload the given file to the document root of the domain for verification .
5.Once verification is done SSL cert will be available to download .