On a related note, I've been meaning to renew my photo card since we moved 12 years ago but never got round to it.
In theory I know this renders me liable to a fine if stopped by the forces of the law but it's never caused a problem. I did go to the post office once but they didn't have a form...
You have to send your old paper licence to DVLA - they don't remind you. Long time since I had to but I suspect there is a form and a fee. It'll be on their website.