The sump plug is located on the base of the engine. You may need to remove the undertray
Undo the fixings
Here's the sump plug
Don't forget to place a suitably sized receiving tray beneath
Using a 19mm spanner or socket, 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 fit a new sump plug and washer. Do not over tighten