If you need a grid certificate, you can obtain one through the UK Certificate Authority Portal:
The portal includes a link to the CA helpdesk, which provides help and advice regarding obtaining and managing your certificate. John Watt
in IT Services is the local Registration Authority (RA), and can provide support with this process; you will also need to visit John to show identification when you first request a certificate. PPE IT support
can also provide some assistance with this process.