Here is the airbox before anything was done (the sticker on top is my K&N sticker):

Now for the actual instructions:
1) Remove the MAF sensor plug. Grasp the plug and press down on the rear of the clip, where my thumb is in the photo:

Pull the plug back, as shown below:

2) Remove the green plug on the right side of the airbox. Grasp the plug and press in on the top, where my thumb is:

Pull the plug straight up, as shown:

3) Unscrew the clamp holding the large air hose onto the airbox. Be sure to place a finger underneath, so that the nut does not fall down and get lost in the bowels of your engine compartment:

Set the bolt and nut aside to reattach later. It will be easier to remove the hose once the lid is free from the box.
4) You can let the connectors removed in Steps 1 and 2 dangle off to the side as shown, to keep them out of the way:

5) Locate the small hose coming in to the front left side of the airbox lid:

Pull the hose off:

6) Undo the 4 clamps holding the box lid on, then remove the lid:

Remove the large air hose from the lid (work it off carefully, rather than just tugging until it comes off), then set the lid aside.
7) Here is the open box with the filter in place (I have a K&N filter):
