You will need to remove car's undertray / open the sump access cover
Undo the fixings using a phillips screwdriver
Don't forget to place a suitably sized receiving tray in place
With an oil catchment tray in position, use a 17mm spanner or 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
Replace (new) sump plug and washer. Do not over-tighten. Replace the undertray