Inlet pipes slide over existing intermediate pipes and align flush with the muffler, however two inlets must be welded on to ensure a complete seal. You'll also need to cut the old resonator as close to the welds as possible. The intermediate pipe factor heat shield must also be removed to complete the weld if a good seal is to be achieved. It's a good product, but it's far from "plug and play". If you don't have a welder I suggest you take one to a fume hood shop to complete the installation.