This lift kit is easy to use. First, make sure your vehicle is parked on a flat and stable surface. Follow the installation guide that comes with the kit to properly install the lift kit on your 2011 - 2014 Duramax vehicle. Since this is an open - box item with scratches, inspect it carefully before installation. Remember, as it's a final sale product, there are no returns. For maintenance, regularly check the bolts and connections of the lift kit to ensure they are tight. Clean the kit occasionally to prevent rust and damage. If you notice any issues during use, consult a professional mechanic.