Hi Riff! Thank you for your question. Please follow the steps below to deregister your vehicle.
1. Go to http://www.onemotoring.com.sg/ 2. Navigate to Selling/Deregistering > Deregister a Vehicle
3. Scroll down to the button "Deregister vehicle"
4. Log in via SingPass and follow the steps there.
You will then need to scrap/export your bike within 1 month of your deregistration. You may do so via Motorist's Scrap/Export service, which you can learn more about here: https://www.motorist.sg/scrap-export-car