Just came back from a 400 mile round trip and the car performed beautifully as expected.

However, on the way up I got a yellow BRAKE LIGHT warning and sure enough, the left rear brake light is burnt out and I need to replace the bulb. Thing is, when I look in the trunk there is no neat little door in the trunk liner to access the bulbs.

So, how do I go about replacing this bulb (outermost on the left side)?