strength because it might be straining.
put the jack under the vehicle. many vehicle frames have exposed metal at the bottom specifically for the jack.
raise the vehicle with the jack until the flat tire is approximately 6 inches above the ground. if on a soft ground, place a wooden plank beneath the jack to prevent it from settling under the weight. remember to never put any part of the body under the car.
remove the lug nuts. you can probably do this with your hand since they are already loose.
remove the flat tire from the hub. use both hands and pull it towards you then put it somewhere safe.
mount the spare on 