connect one end of the red cable to the positive terminal of the empty battery
connect the other end of the red cable to the positive terminal of the full battery
connect one end of the black cable to the negative terminal of the full battery
start the car with the full battery
with the other end of the black cable, touch unpainted metal parts under the hood of the car with the empty battery. if a spark appears, connect the end to that metal part
let the car with the full battery run for at least 2-3 minutes
try to start the car with the empty battery
if it does not start, let the car with the full battery run longer
if it does not start after half an hour, then call a mechanic
disconnect the cables in the opposite order, starting with the end of the black cable that is connected to the car with the empty battery