Press the saw against the very bottom of each spindle, also known as a baluster, and saw each one away from the step. Make sure to get the saw as close to the base of the spindle as possible, and saw gently, in a straight line. The spindles are nailed to the step, so sawing them away from the tread will ensure their easy removal.
Dislodge the filler, a dried putty, located between the top post and each spindle, with a chisel. Then tug the top spindle out of position with your hands. Often, spindles are glued to a banister, so exert some force to get them out of position.
Repeat the process to remove every piece of filler and pull out every spindle. As you pull out each spindle, mark it sequentially to simply reinstallation.
Saw each post away from the floor, then pull each post out of position. The posts hold the railing in place. Some posts are secured with L-brackets at the base; in that case, remove the screws from each L-bracket with a Phillips screwdriver, then just pull the loosened post from the floor.
Unscrew the U-shaped straps on the underside of the banister from the brackets on the wall with a Phillips screwdriver. The banister is now uninstalled.