There will be a black tank up in front of the vehicle. Make sure the car is cold. Locate the cap, open it, if it is very low, you can add water.
You don't want to fill it all the way to the top, but at least 1/2 way up. The coolant needs room to go up and down with temperature.
Lastly, watch for leaks after you fill the system, coolant should not evaporate or be low.
Eric Sevim - ASE Master Certified Technician
A+ Japanese Auto Repair - San Carlos CA 94070