You will need to remove the undertray to access the sump plug
Carefully remove undertray fixtures and place carefully to one side
Do not forget to have a suitably sized receiving tray in place.
With an oil catchment tray in position, use a 19mm spanner or socket to carefully remove the sump plug. Fully drain the oil.
When the sump has emptied, wipe clean the sump plug area with a paper towel