If you are quite comfortable working on cars you can do this. The in cabin air filter is accessed through the glove box opening after removal of the glove box.
There is a small panel covering the right hand side of the glove box which will pop off if you pry lightly with a standard screwdriver
Then there are eight Philips head screws which must be removed. Three are at the bottom of the glove box, three more are inside on the top and two are located inside at the rear top of the glove box. Once these are removed and the glove box is pulled out the filter is accessible, but not very easily seen.
It is located on the far left side and covered by a black plastic cover. You can reach in and push up lightly on the plastic cover removing it.
The opening is smaller than the filter and that makes removal and replacement difficult, but the filter is flexible and the pull tab can be used to extract the old filter. The new one can be squeezed and pushed into place with the air direction arrow towards you (the same orientation as the one removed). Replace the plastic cover and reinstall the glovebox by installing the eight screws and the side cover.
The 1999 Nissan Maxima does not have a cabin air filter. It never came with one.
Yes, it has a filter. Click the link for instructions.
Behind the glove box
2000 Nissan xterra cabin air filter
is there a cabin air filter on 1997 maxima
take of glove compartment then you see the cabin filter
Filters for a Nissan Maxima need to be changed every 15,000 miles. To change it remove the screws, release the retaining clips, and remove the glove box bulb.
in glove box
where is cabin filter
The cabin filter was introduced to Nissan Frontier's in 2002.
It may be located behind your glove box. You should see a thin panel type plastic piece. that would be your filter. Careful when you pull it out so you don't get sand and leaves inside the blower motor housing.
I doubt that a 1993 model has a cabin filter. Go to a parts store and ask for one. If it has one they will sell it to you. Purolator cabin filters come with instructions.