Change the oil in a Kawasaki Mule by warming up the engine, shutting it off, placing a drain pan under the vehicle, removing the drain plug and fully draining the oil. Replace the plug and engine oil. Replace the oil filter as well, if desired.
Although warming up the engine prior to draining the oil is not necessary, doing so decreases the oil's viscosity and picks up any particles of sediment or hardened oil inside the engine. Only warm up the engine for a few moments to prevent it from becoming hot and unsafe.
Replace the oil filter by removing the old filter using a special oil filter socket and any standard ratchet. Hold a rag under the old filter during removal to prevent any trapped oil from spilling onto the floor. Ensure a good seal by applying a small amount of fresh oil to the new filter's gasket. Screw the new filter into place, and torque it to 9.8 Newton-meters or 87 pound-inches. Do not over-tighten the new filter, as doing so can damage both the filter gasket and threads.
Refer to your user manual or Kawasaki's website to find the correct oil weight and viscosity for your Mule. After installing the new filter and replacement oil, run the engine for a few minutes, and check for leaks.