A vehicle's air filter is a replaceable cleansing unit. In most cases an air filter can be replaced in under 5 minutes. The air cleaner in your car or truck should be changed every 3,000 miles or sooner depending on driving conditions. Changing your air filter is easy! Remember, always use protective eye wear and gloves when doing any car repair. First locate the air filter housing; this is where the air filter element resides. To locate the air filter housing look for the engine air intake tube. Next, remove the air filter housing retainer clips or screws and remove the air filter housing top. Replace the old air filter with a new air filter and reassemble. (Note: be sure you clean out any leaves or debris inside the air filter housing upon reassembly)