To maintain the performance of your HVAC system, it is recommended by the manufacturer that you change the cabin air filters at the specified interval. To do this, start by removing the glove compartment. Next, remove the bolt which secures the cover of filter drawer in heating/air conditioning unit and take off that cover. Afterward, pull out these two filters. Install new ones that are marked with arrows indicating which side is to be kept down. The new filters are such that when installed, their ends marked with arrow should be visible. Note: Putting one before another and moving it as far as possible towards right before installing another after it. The rest of installation process is just doing opposite of removal process.