I see some people asking how to open the door to drop down, so I'll just add how. Once you have the drones, there are 4 neon coil lamps on top of 4 buildings (pink, orange, blue and green) you'll notice the door has those same lights and power running from each. Using a drone, you don't have to let go, just smash into the glass of each coil, it will break and the power from that one will turn off.
Once all 4 are off, just head on over to the big green hole and drop in. The level will end and the achievement will unlock shortly after (just stay on the start menu screen)