Wing drainage

[v8 animal]

Cleaning my car today and noticed 2 drainage holes in the front wing poked them with a screwdriver to make sure there clear.1 hole has something inside when i poke about with the driver something moves possibly a bolt.(driver side)
How do you get in the caviety can't see how you do it.
Any clues anyone?
V8 Animal

[spend]

Headlamp out + long arm....... Remove brake cylinder etc + long arm..... Most people are put off by this :-)