Summarize the following:
. Locate the petcock on the bottom corner of the radiator and open it with a container beneath it to catch the draining coolant and water. You may also want to disconnect the bottom hose going into the radiator to drain it. Close the petcock and reconnect the hose once it’s done draining.  Add a 50/50 mixture of water and coolant to the radiator and it reaches the full line on the reservoir. Make sure to use the correct kind of coolant for your vehicle. If you are unsure, you can find that information in the owner’s manual or on the manufacturer’s website. Some newer vehicles have different interval requirements for oil changes, but if you’re unsure, 3,000 miles is a good rule of thumb. Slide a container beneath the vehicle’s oil pan, then locate and remove the oil drain plug (the only bolt in the bottom of the pan). Allow it to drain completely, then reinsert the drain plug.  Unscrew the old oil filter and screw on a new one in its place. Then refill the engine with the correct amount and type of oil, which can be found in the vehicle’s owner’s manual or on the manufacturer’s website.

Summary:
Drain and replace the coolant Change your oil every 3,000 miles (or as directed).