The sump plug is located on the base of the engine. It is accessed underneath the car. You will need to remove the car's undertray
Undo the fixings
Here's the sump plug
Don't forget to have a suitably sized receiving tray in place
With an oil catchment tray in position, use an 8mm Allen key or socket to carefully remove the sump plug and fully drain the oil. When the sump has emptied, wipe clean the sump plug area
Replace (new) sump plug and washer. Do not over tighten. Replace undertray
