You will need to remove the sump cover
Undo the fixings -use a 12mm socket. Caution! The sump cover is heavy and should be properly supported
Don't forget to place a suitably sized receiving tray beneath
Using a 17mm 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. Replace the sump cover