The change of name on your Singapore identity card has to be done at Immigration & Checkpoint Authority. You need to bring along the Deed Poll and your original identity card to change your name. The change of name and the replacement of a new identity card have to be done within 28 days after the day when you executed your Deed Poll.
This Deed Poll is in Microsoft Word format and the Deed Poll enables you to change your surname, your given name and abandon the use of Hanyu Pinyin name.