1999 Honda Accord cabin air filter replacement.  This is an easy task that should take you about 20 minutes total.  You will need a #2 phillips screwdriver, and a small flathead screwdriver.

CAUTION: You will be working closely around the stupid airbags, which have been known to detonate for no apparent reason, so be CAREFUL!!  I hate the fact that I am forced to drive around with explosive devices in my car that can kill and maim, are very expensive, that I dont want there, and the only reason they are there is to protect people who are too damn stupid to wear their seatbelt anyway.  Enough ranting, lets get on with changing the filter.  Click on the thumbnail images below to see the larger version.

Start by removing the ashtray, then the two screws above the ashtray as shown here:

Carefully pull the panel underneath the radio out, and then disconnect the connector - its hard to reach, and this is a job for little hands.....there is a small tab on the car side of the connector which must be depressed, and the connector will separate easily.  This is where your child can help you!

Now remove the screw holding the "knee" panel below the glovebox:

Remove the panel covering the fuses on the far right of the knee panel, and the two screws there.  Note, the two machine screws at upper left of this picture do NOT need to be removed:

This one is a machine screw:

Gently remove the knee panel.  It will be loose from the bottom, and you will have to pull it straight back towards the rear of the car.

Now, open the glovebox and pry off the little square covers as shown.  Insert a small flat screwdriver into the slot at the bottom of the little cover, and gently shove it in until it stops, then lift up a bit and the cover will pop right off.  Note that the covers are not the same....there is a right and a left:

Remove the two screws, one under each of the removed little covers:

Now remove the two screws at the top center of the glovebox, as shown:

Now remove the 4 screws on the bottom of the glovebox, as shown below.  One is at the end of the screwdriver, the other three are on the bar above where the screwdriver is, where you can see the word "HONDA":

Now remove the glovebox.  It may require a bit of gentle wrestling to get it to come out.  Shouldnt take much force, though.  Lift it upward and out.

Next, remove the metal bar across the bottom of the passenger knee area as shown.  There is a machinescrew at each end of this bar which must be removed (one is shown below), and on this particular vehicle, they were extremely tight.  There was also a ground wire attached to this bar, just leave that attached - move the bar out of the way.  If you cannot loosen these two machine screws with a screwdriver, you may need to clamp a vicegrip on them to break them loose.

Now you can access the filter housing, as shown below - the filter cover is the ladder-looking thing in the center - remove the bottom first, and it will lift right off, revealing the filter assemblies.

The filter assemblies revealed:

Pull these out carefully, bottom one first.  The top one will drop to the position vacated by the bottom one, and then you can slide it out.  The filters are in a plastic "frame", so you discard the old filter elements and replace the new filter elements into the original frames, and reinstall.  Below are the original filter elements still in the frames, with the new filters on top.  YEEEeeeach!!  This car was previously owned by a chainsmoker.  Imagine what this idiot's lungs looked like!!

Push the old filters out of the frame, and gently replace with the new.  Be careful to note the "AIR FLOW" markings with the arrows to show which way the filters go into the frames and the frames back into the AC unit.  You must inset one frame/filter and hold it in place at the top while you insert the lower one.

Reverse this whole process to button everything back up.

Good luck!