The sump plug is located on the base of the engine, and it is accessed from underneath the car
Don't forget to place a suitably sized receiving tray underneath
Use a 14mm 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
Replace (new) sump plug and washer. Do not over-tighten
Find a Haynes product for your Nissan:
Search by registration mark
Search by make & model