Air Box Removal
The engine intake air boxes on an Aston Martin are at the front of the car, directly below the headlights. They're put there for a number of reasons, and convenience isn't one of them. Removing the air boxes isn't terribly difficult, and the process is similar for both the Vantage and DB9/DBS.
Jack and jack stands (or a lift)
Flat-head screwdriver (optional)
T30 Torx bit
T40 Torx bit
Ratchet and 6" extension for the above bits and sockets
Break the lug nuts loose on the front wheels. You only need to rotate them a single turn - you're just doing this so you can remove them after the car is off the ground. If you don't loosen them, the wheel will likely spin when you try to loosen the lug nuts.
Get the car on jack stands or use a lift. Make sure the car is stable, then remove the front wheels.
Remove the front undertray by using the T30 and T40 Torx bits and the ratchet to remove the bolts holding it in place.
Use the T30 Torx bit, ratchet, and Philips-head screwdriver to remove the front fender liners. You can do this job with the rear half of the fender liners still bolted in place, but it's much easier to take the extra minute to remove them entirely.
Disconnect the corner marker (this gives you more space to move around and reduces the risk of damage to it). Disconnect the MAF sensor. To do this, slide the red safety tab up, then you can press in the connector's tab to release it.
Use the 8mm socket, 6" extension (as needed), and ratchet to remove the three 8mm bolts holding the air box in place. You can now move the air box around a bit, just be careful not to damage anything in the surrounding area.
Use a pair of flat-head screwdrivers to release the alligator clamp securing the MAF tube to the corrugated air ducting, then carefully separate the MAF tube from the corrugated air duct. The entire air box assembly can now come out of the car.