If you already requested certificates on one way or another, and/or you are a confident person, just:
1. Go to http://www.digicert.com/sso;
2. Choose your institution, and login;
3. Request a Grid Premium certificate;
4. You can now export the certificate from your browser if needed.
Choose your institution, e.g., by typing 'VUB' or 'Vrije Universiteit Brussel'Press the button Start single sign-onLogin with your institution credentials. This page will look different for different institutions.Choose a Premium Grid certificate, and press the button Request certificate.If you see this, your request succeeded.If you go back to http://www.digicert.com/sso, you'll see an overview of your certificates. In case of a security problem (e.g. stolen laptop), you can also revoke the certificate here.