grid-cert-renew [-help] [-nopassphrase] [...] <challenge text>

    This command creates a request for renewal of your Globus credentials.
    Optional arguments:
      -help, -usage        : displays this message
      -debug               : extra output (if problem occurs)
      -nopassphrase        : do not encrypt the new private key file 
      -sslexec    <path>   : location of SSL executable (openssl)
      -oldcert    <path>   : location of old certificate
      -oldkey     <path>   : location of old (private) key
      -newkey     <path>   : location of new (private) key
      -newcertreq <path>   : location of certificate renewal request
      -version             : prints the version 
    Required Argument:
      <challenge>          : challenge text, as per email instructions.