This guide describes how to replace the engine oil and oil filter on a Royal Enfield Himalayan 400. Obtain 2 litres of Motul 300V SAE 15W50 oil and Royal Enfield oil filter P.N. 888464. Position the motorcycle on the centre stand. Start the engine, allow it to reach temperature, and then switch off. Place a container for the used oil underneath the engine. Use a ratchet and a 10 mm socket to remove the screws from the engine guard, detach the tube using pliers and remove it. Use a ratchet and a 19 mm socket to remove the oil drain plug located on the left side of the engine. Allow the oil to drain and clean the plug thoroughly. Remove the two 10 mm screws from the plate and extract the filter located inside the engine in a horizontal position. The oil filter is located on the right side, under the round cover held by three 10 mm screws. Remove the three retaining screws with the ratchet and extract the filter cartridge, replacing both the filter and the gasket provided with it. Refit the oil drain plug. Open the oil filler cap located on the right side of the crankcase. Pour in the oil according to the level indicated at the inspection hole. Start the engine for one minute and switch off. With the engine cold, recheck the level.