On single carburettor models, start by pulling the hose from the intake preheater and disconnecting the vacuum hose. Then, slacken the air filter box body strut nuts. Withdraw the air filter box from the carburettor and disconnect the crankcase breather hose. Release the cover clips and extract the element. It is important to note that the maximum operating mileage for an element is 10000 miles (16000 km), so it should be renewed at this point. In dusty conditions, it is recommended to renew the element more frequently. Before installing the new element and refitting the assembly, make sure to clean out the interior of the air filter box casing. On twin carburettor models, remove the intake scoop at the rear of the carburettor, pull off the breather hose, and loosen the connecting hose clamps at the carburettor. Release the air filter box securing bolts and remove the assembly. Finally, release the end cover clips, extract the element, and renew it following the same steps as described before.