Remote Fuel Filler Door Release
The fuel filler door can be opened from inside the vehicle by pulling up the fuel filler door release lever located on the floor at the front left of the vehicle.

Location of the remote fuel filler door release lever
If the fuel filler door cannot be opened due to ice, lightly tap or press on the door to break the ice and open it. If necessary, use an aerosol de-icer.
Turn the fuel cap counterclockwise to open it.

Direction of turning the fuel cap to open
Install the fuel cap by turning it clockwise until it clicks.
If the fuel cap cannot be opened in cold weather because it is frozen, press on the cap or lightly tap it.
Gasoline vapors are toxic. Always turn off the engine before refueling. When handling fuel, keep open flames away from the vehicle. If the fuel filler cap needs to be replaced, install only the genuine Hyundai cap designed for your vehicle. Sometimes a slight "hissing" sound can be heard when the cap is loosened at high ambient temperatures. This is normal and not a cause for concern. When opening the fuel filler cap, always turn it slowly.
Test yourself
A quick Hyundai Accent quiz: every answer comes with an explanation and a link to the manual page.