The sump plug located on the base of the engine; it is accessed underneath the car
Don't forget to place a suitably sized receiving tray beneath
Using a 6mm Allen key 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 refit a new sump plug and washer
Find a Haynes product for your Volkswagen:
Search by registration mark
Search by make & model