Need to know how to get the air out of the brake lines.

You will need to bleed the brakes. The easiest way to do this is to have a second person if you don't have a power bleeder.
You should have the vehicle on a level surface, then starting at the farthest wheel from the master cylinder (right rear) have your helper pump the brakes several times until the pedal is firm. Then have your helper keep constant pressure on the brake pedal while you loosen the bleeder (a small nut with a hole in it located towards the top of the brake backing plate on the rear). If this vehicle has 4 wheel disc brakes the bleeder will be located at the top or highest portion of the caliper. You should check that you have a full master cylinder of Dot 3 brake fluid and make sure the cap is on securely after you have bled each wheel. Running the master cylinder out of fluid will only cause you to have more bleeding.Only crack the bleeder open far enough till you see, feel or hear air come out but make sure to tighten it before you helper reports the pedal is on the floor.
You will need to be quick. Repeat this on this wheel till you get a solid stream of brake fluid coming out. Then move to the left rear and repeat.
Once done on the rear you will need to remove the tires from the front to have access to the bleeders on the caliper.Again starting on the left front repeat the procedure then move to the right front.
By the time you are finished your pedal should be firm and towards the top. If its not you may need to replace the brake pads and shoes and have the rotors turn or replaced. If you have rear drum brakes you should make sure these are properly adjusted up also. This too can cause a spongy pedal.