Buy the right gasket, and appropriate gasket sealer , and an appropriate oil filter and quantity of correct engine oil from an auto parts store, or dealer, then get the car home, drain the oil by removing the drain plug on the oil pan, let all oil drain, then replace the plug. MAke sure you have a torque wrench. Call auto dealer service department for the correct torque secification for the oil pan bolts, this is EXTREMELY important. Remove the oil pan by loosening up each bolt in a alternating or star pattern, then remove each bolt i a similar fashion. Don't lose track of which bolt goes where, yes, I mean draw a diagram, then peal off the gasket, clean both the oil pan surface and engine block surface where the gasket meets, DO NOT SCRATCH OR SCRAPE THE SURFACES, clean them with paper towels, and any gunky or stubborn material, you may use a brillo pad to remove. Then, apply the gasket sealant to all mating surfaces, not the gasket itself. Then loosly place the pan, with gasket already in place on it, up to the engine block. Then, in as much of an alternating or star pattern as possible, loosely (finger tight) re-install the bolts. Then, WITH A TORQUE WRENCH, evenly tighten in the alternating pattern, then torque to their specification, call your dealer for the spec. then add remove your old oil filter, and add several ounces of engine oil to your new oil filter, ad install the filter. Finally, add the correct amount of engine oil, and inspect repair for leaks allow engine to warm up, then shut off and let cool for twenty to thirty minutes, check again for leaks. Good Luck check out http://www.autozone.com/shopping/vehicleSelect1.htm and look up your vehicle, and remember, this gets to be a messy job, so you may want to lay cardboard out before you start, especially if you are parking the vehicle to work on it where you will be leaving it the next day or so, so as to be able to identify if any oil has dripped onto your driveway, or not. Because you will indefinately spill alot of oil when doing the reair.