The air filter housing is near the left-front of the engine compartment. On 350Z models, release the two clips securing the filter cartridge into the housing, remove the cartridge and filter. If you're working on a G35 model, remove the inlet air duct, then release the two clips securing the two halves of the air filter housing. Remove the filter. Inspect the outer surface of the filter element. If it is dirty, replace it. If it is only moderately dusty, it can be reused by blowing it clean from the back to the front surface with compressed air. Because it is a pleated paper type filter, it cannot be washed or oiled. If it cannot be cleaned satisfactorily with compressed air, discard and replace it. While the cover is off, be careful not to drop anything down into the housing. Never drive the vehicle with the air cleaner removed. Excessive engine wear could result and backfiring could even cause a fire under the hood. Wipe out the inside of the air filter housing. Place the new filter into the air filter housing, making sure it seats properly. Installation of the cover is the reverse of removal.