Grease your ball joints each time you change or rotate your tires. At the least, do this once a year.
Jack up the car and install jack stands and remove the tire. You can leave the tire on but this is much easier.
The front has one grease Zerk on the steering ball joint.
The rear has two, one near the back, and one near the front.
Clean these up real good as they will be covered in grime.
Put the grease gun end on the zerk and give it 1 to 3 pumps. Do not pump until you see grease coming out of the rubber boot. When you do that you have burst the boot and the grease will leak out and water will get in. Watch the boot, it will expand a little.