Most Crane toilet parts replacements require turning off the water supply, flushing the tank and emptying any remaining water before beginning. Once the tank is empty, replace a flapper valve by removing the old unit and attaching the new one over the ears on the overflow tube. Once the flapper is in place, attach the chain to the flush lever, and adjust so the toilet flows correctly.
If the toilet runs continually, replace the old fill valve with a new one. Place a bucket under the supply line connection, and remove the line from the bottom of the tank. Loosen the retaining nut under the bottom of the tank, and lift the old valve out of place. Place the rubber washer over the threaded end of the new valve, and slide the threads through the hole. Finger-tighten the nut to hold it in place, and reattach the supply line.
Water leaks around the base of the toilet often indicate a problem with the wax ring. After removing as much water as possible from the tank, use a plunger to force most of the water from the bowl. Remove the supply line from the tank and the closet bolts from the base of the toilet. Remove the toilet and the old wax ring. Place the new ring on the bottom of the toilet, and move it back into place. Press firmly on the toilet to seal the new ring, and replace the closet bolts and supply line.