I took some pics the last time I cleaned it, so you can see what's involved. You need a 10mm socket and a Philips head screwdriver.
Note: This is how I did it and it is not intended as an instructional guide. If you do try it, it's at your own risk. It's essential that you do not allow foreign objects to fall into your intake as they can be drawn into the engine and destroy it.
Removing the front section of the air intake, with the 10mm socket:
Loosening the clips around the "accordion" section of the air intake in front of the throttle body:
Removal of the tube leading to the same section. It slides out:
Then came the tricky bit, pulling out the section that was just disconnected. It needed to be squeezed together to get it out. Here it is removed:
Here's a shot looking into the throttle body, showing the butterfly valve:
It was too cramped to show pics of the actual cleaning, but I cleaned the area using a solvent based fuel system cleaner and an old toothbrush. I also moved the valve open and cleaned as far as I could reach in and around the valve.
It's easy to knock dirt into this area as the middle section is replaced, so be careful to clean it out before tightening everything up.
I did not start the engine until everything was re-connected, nor did I spray cleaner into any other part of the intake.
If you are doing this, It may be worthwhile cleaning the MAF sensor while you are at it to get the most benefit.