This thread was originally posted by Soccerbrace on the ClubXterra forum. All credit goes to him.

It will take you a while to read this but it can get done in much less than an hour. Don't be afraid to try this yourself. You can and will succeed! So stop trippin boo.
First, I have OWNED a K & N FIPK so I am not just relaying information. I want to tell you guys how to (IMHO-in my honest opinion) get the same performance of an after market intake using your stock intake system.
Start by cleaning your MAF (Mass air flow) sensor. I included a video. This guy on the vid is not me so I am not claiming to be the guy on here. Nor is that an Xterra, but the concept is nearly the same. Bear with the guy, he is about in depth as I am with the instructions. The MAF cleaner claims to give 4-6 hp at the wheels. :?
Video- http://videos.streetfire.net/video/4...6f015c3dac.htm
Here
(circled) is the MAF sensor. Pull it with a couple of philipps head screws.

Now remove your resonators and plug the existing holes.
Here are a few videos of vehicles with their resonators removed. Do not worry, we will sound throaty not ricey.Promise!:P
http://www.youtube.com/results?searc...&search=Search
My favorite is this before and after:
http://www.youtube.com/watch?v=9tVAZeEgFVg
You will see the term "T-Pipe" used quite frequently throughout this post. Here it is. It is located between the left front headlight and the air box.

You must buy the following test plugs. You can find these in the plumbing section of Home Depot. I only have 2 because I JUST installed a snorkel. You have to get 2 plugs -- one 2" plug and one 1.5" plug. MAKE SURE YOU GET THE GALVANIZED METAL PLUGS!

Start by popping your hood. This is what you will see. (duh) The circled area is where you will be working.

In the end, you should have these 3 thingamajigs out.

From left to right, there is the baffle (located in between the inner and outer fender). In the center is the resonator attached to the main intake hose and mounted on the wheel well, and on the far right is the resonator mounted to the top of the radiator from the T-Pipe.
First, remove the resonator attached to the main intake hose. It is outlined in the picture below.

We will start by loosening the hose clamp circled in yellow by using a Phillips-head screwdriver.

Loosening the hose clamp:

Next we will LOOSEN the lower resonator screw. Use a 10mm wrench, or a nut driver, or a stubby screwdriver such as the one pictured here:

You will need to get to the screw in the following picture. It is located underneath the brake booster on the wheel well.