If you just want to clean up the files in /etc/letsencrypt after issuing from staging, you should be able to simply delete /etc/letsencrypt/accounts/acme-staging.api.letsencrypt.org. In almost all cases, this should be fine, however, it depends on what you’ve done with Certbot in the past. To verify that this is safe to do, run this command:
sudo grep -r $(sudo ls /etc/letsencrypt/accounts/acme-staging.api.letsencrypt.org/directory) /etc/letsencrypt/renewal/
If it produces no output, deleting /etc/letsencrypt/accounts/acme-staging.api.letsencrypt.org is safe and won’t cause any errors in the future.