How do you replace spark plugs on a 2002 dodge durango?

First label each spark plug wire with a piece of tape or tag indicating which hole it attaches to. This is very important because you might mix up the firing order otherwise! Next, disconnect the negative terminal on your battery so you don't shock yourself. To remove the wires, grab each by the boot and pull firmly outward. They should pop off of the plugs. Sometimes they are a pain but try not to jerk them back and forth too much or pull by the wires themselves because you can break a wire and the harness kits aren't cheap. After the wire is removed, use a socket wrench with a sparkplug socket to unscrew each plug. Plug sockets have a rubber seat that protects the socket but you can get by with a normal socket, just be careful not to damage your new plugs when you replace them. I'm not sure exactly what size but there are generally only 2 different sizes that most cars use. Getting to all the plugs with a socket wrench can be an acrobatic feat on a V8 so try different size extensions and ones with varying angles if available. Buy new plugs and a gapping tool. Ask your auto shop what the proper gap is for your vehicle and carefully bend the flat metal strip on each spark plug to the proper gap size. A good trick to get a spark plug started in the hole properly and not misthread it is to stick a 6" piece of rubber tubing over the end and use it to start turning the plug in the hole. If you misthread it, the rubber will slip and you won't screw up your entire head. Tighten each spark plug firmly with the socket but not so tight you break the threads out. Finally, replace the wires. When you start your car if it jerks around like crazy, you screwed up the firing order and you'll have to switch the wires around.