I cannot open the cover. I tried to twist it anti clock-wise, or clock-wise, or pull down. No success. Can anyone help? Thanks.
Answered by OP in comments:
I did it! There is something like a little groove at the side - at the connection between black and white parts - wherein I slotted a screwdriver, twisted it, and the light cover pulled off. Eureka! – Lukman Dec 17 '16 at 12:16