You may need to remove the undertray to access the engine sump
Undo the fixings - use a 10mm socket
Don't forget to have a suitably sized receiving tray in place
With an oil catchment tray in position, use an 8mm Allen key socket to carefully remove the sump plug and fully drain the oil.
When the sump has emptied, wipe clean the sump plug area with a paper towel and refit the sump plug and washer. Do not over tighten