You can delete a specific iptables rule in the POSTROUTING chain using the following command:
iptables -t nat -D POSTROUTING <rule_number>
Replace <rule_number> with the number of the rule that you want to delete. You can find the rule number by using the iptables -t nat -L command to list the rules in the POSTROUTING chain.
Note that after deleting a rule, the numbers of the following rules will change, so you may need to use the iptables -t nat -L command again to determine the correct rule number.
It’s also recommended to make a backup of your iptables rules before making any changes, so you can easily restore the previous configuration if needed.