How to Change an Air Conditioner Filter RV Air’s Step-By-Step Installation Instructions Not sure how to change an air conditioner filter? Watch our founder, Eddie Rice, install an RV Air Filter, or scroll below for step-by-step photos. Step 1: Remove your AC Air intake grille then remove the old filter Step 2: Make sure the GREEN SIDE of the RV Air filter is facing UP Step 3: Properly align the RV Air filter on AC grille and reinstall into your RV