Recently installed mine on my very first AR, figured I'd take some pictures along the way to show others how to do the same install. It's super easy, and the kit is under $5!
Tools you will need; 1/16" punch, something to tap the punch with(not a full sized hammer), vice grips, some cleaning patches or electrical tape.
We're going to start with the bolt carrier group already removed, if you don't know how to do this....refer to steps 4 through 9 at the following link. Link also covers my first few steps, but I have them listed anyways in order to have a more complete walk-through on the install process.
Basic field-stripping instructions(separating upper from lower, removing BCG, etc)-
http://groups.msn.com/TheMarylandAR15ShootersSite/fieldstripping.msnw
Now, on to the install process.
Step 1. Remove the firing pin retaining pin. You shouldn't need anything other than the punch for this, since that pin tends to come out easily. It can only be pushed out one way, since it's a cotter pin(loops at one end).
Step 2. Remove firing pin.
Step 3. Push bolt in and turn clock-wise, then turn the bolt cam pin 1/4 turn either way to pull out.
Step 4. Pull bolt out from carrier.
Step 5. Remove extractor retaining pin. You may need something to tap the punch with, just don't use a big hammer because you could damage the pin, or the bolt.
Step 6. Remove extractor, should come right off now that the pin is removed. Take note of the small spring with the blue or black plastic insert in the middle, on the bottom side of the extractor.
Grab spring, and turn counter-clockwise while pulling to remove it + the extractor insert. Don't worry about pulling too hard, this stuff won't break and if it does...well, these things are about to get replaced/upgraded anyways.
Step 8. Installing the actual kit...I only took one picture for this, so I'll cover several things in this step. Open the BCM Extractor Upgrade package, and you will find 3 little parts(DONT DROP THEM!)...a better extractor spring + black extractor insert + o-ring(Your rifle may not have had an o-ring like this one, that's OK).
Put the new insert in the same area you removed the original from on the extractor, bigger side goes in. Now put the new extractor spring over the new extractor insert, and give it a little bit of a clockwise turn to "lock" it in. Last, put the new o-ring over the new extractor spring. Sorry for the blurry picture, but everything looks about the same as it did when you removed the extractor...except the new spring is a little bigger and now there's an o-ring around it.
Step 9. Place your newly upgraded extractor back on the bolt, and notice how you can't easily hold it down with your fingers to put that extractor retaining pin back in, due to the new spring.
This is where you'll need some sort of padding and a pair of vicegrips, the padding is used between the bolt and the jaws of the vicegrips to keep from damaging anything. Once you get that extractor retaining pin inserted, re-assemble everything and enjoy your newly upgraded rifle that YOU did the work on yourself!
Thanks to ThomasH and DCN1982 for offering me info last week when I first purchased this kit and had no idea what I was doing.