Edit the cron tab:
crontab -e
and copy this line at the end of the file and save it (WARNING:modify it with the correct path):
*/30 * * * * php /var/www/html/modules/reseller/cron-shop.php
Now this script searches for expired game homes every 30 minutes, and will stop and remove them if they are expired. If you would like to do this at midnight every day instead of every 30 minutes you should use
0 0 * * * php /var/www/html/modules/reseller/cron-shop.php
TIP: Searching in google, for example, "crontab run job once a month" you will find the correct code to search expired homes and remove them every month.