You will have to remove your drivers side air filter housing to access the bleed plug. You will need a Phillips screwdriver to turn it.
Drain your coolant. Then remove your drivers side air box and remove the bleed plug. Close the petcock once the coolant is done draining then slowly fill the radiator. Have the bleed plug and your screwdriver ready to go so once coolant starts coming out of the bleed plug hole, you can put the bleed plug back in. Once you put the bleed plug in, continue to fill the radiator slowly.
Once the coolant is above the radiator fill neck, put the radiator cap back on. Fill your plastic coolant reservoir between the minimum and maximum lines. Then, start your car and let it get to operating temperature and feel your lower hose to ensure the T - stat has opened. Now, check and correct the fluid in the plastic reservoir once more then put the cap back on.
Finally road test your Z and monitor your coolant temperature.
Turn your heater on to help check if there is air in the system. Check your coolant in the plastic reservoir once more and correct as necessary.
Then