Air Intake?

There is no "air intake part" per se. Depending on vehicle the intake system could consist of a tube with a hole for air to flow into, a filter element and place for the filter, various resonators, flex tube with or without maf, throttle body or carb horn & parts, intake manifold, and a bunch of other stuff.

I'm sure I know what you mean, but if you mean install a new air filter, its in the box between the air intake and the throttle body. The rest of it really does not get dirty except for the maf and throttle body. It would be best to take those off and use something like carb cleaner spray. The maf is fragile - be careful.