I believe its tucked away underneath the engine - to change it, you should drain the oil from the sump first,there should be a plug underneath that you need remove - then the Air filter would screw off - sometimes tricky to get a good grip so you may need some gripping tool - (Ive used a screwdriver in the past - just stab the filter and use the screwdriver as a lever) - replacement fillter screwed back on and then fill the oil tank again.