I did this by going straight to the database using phpMyAdmin.
This can break stuff however if you don't know what you are doing as it bypasses any syntax or data checks that maybe in Abantecart. If you are starting out though and can afford reloads, start overs, etc..., it maybe easier to just do straight "update" database commands in phpAdmin like:
UPDATE `abc_countries` SET `status`= 0
UPDATE `abc_countries` SET `status`= 1 WHERE `country_id` IN (223)