Look under the hood and find the air filter housing.
Your air filter is usually enclosed in a black plastic casing or housing. It’s either square or rectangular (on fuel-injected engines) and typically has a big air intake hose connected to it. On older vehicles with carbureted engines it will be located in a large round housing sitting on top of the engine.
Remove the top of the housing.
Start by wiping off any dirt, so it doesn’t fall down when you open the housing. Now use the appropriate tool, as indicated in your service manual, to remove the screws and or clamps that hold the top and lift off the top of the housing. If you have an older vehicle with a round air filter housing, remove the wing nut holding the air filter cover and any other clips.
Remove the old air filter.
The old air filter should lift right out. Once you remove the filter, use a clean rag to wipe any dirt and debris from the housing and the seal. Also check for cracks or damage to the interior and exterior of the housing and connecting air intake hose. Be careful that no dirt or debris falls into the carburetor or the intake during this process.
Install the new air filter.
The new air filter goes in just like the old one came out. Put on the top of the housing, replace the screws or clamps, and you’re done.