Instructions
Creating the Tower
Dig a one-block deep hole and place a piston facing upwards in it. Connect the piston to a lever with redstone.
Place another piston behind and to the right of the first piston. This one also faces upwards.
Put a sticky piston behind the second piston, facing towards it.
Put two blocks on the side of the pistons.
Place a piston and sticky piston in the same arrangement on top of the two blocks. On the other side of the pistons, place two blocks. Repeat this alternating pattern as high as you want your elevator to go.
Place glass two blocks in front of the pistons so you don't fall off.
Redstone Wiring
Place a redstone repeater next to the upwards facing piston. The repeater should face the direction of the lever. Place a solid block in front and behind it. Another redstone repeater goes two blocks behind it.
Place a redstone repeater behind the first sticky piston. Set the delay to three ticks. You can set the delay by right clicking the repeater.
Place one more redstone repeater that leads the circuit to the next level. This repeater needs to have a one tick delay.
Connect the repeaters to the lever in the front with redstone.
Repeat the same pattern on the left half of the elevator. This side is always one level above the right half. Place a repeater between the lever and the left side circuitry. The layout is repeated for every level that the pistons are on, all the way up.