This worked for me, many thanks…
made a backup first though JIC,
sudo cp /etc/letsencrypt/ /etc/letsencrypt.backup -r
I deleted the ‘no longer needed domains’ in the three folders…
rm -rf /etc/letsencrypt/live/${DOMAIN}
rm -rf /etc/letsencrypt/renewal/${DOMAIN}.conf
rm -rf /etc/letsencrypt/archive/${DOMAIN}