If you have purchased a domain from us, kindly login to your APC billing account at https://billing.apc.sg/clientarea.php and follow the below guide to do so.
Take note after completing the below process, there is a 24-48 hours propagation period.
Kindly select the radio button "Use custom nameserver (enter below)" and enter the nameserver you wish to change to and when you are done, click on "Change nameserver" at the end of the page to save.
