Raise the corner of the car enough so that you can comfortably work underneath it.

Place a jack stand underneath the frame next to the jack.

Slowly lower the jack so that the car is resting on the jack stand.

Many hydraulic jacks are lowered by placing the open end of the handle over a knob and turning it counterclockwise. Consult the owner's manual for your jack if you don't know how to lower it.

Never work underneath a car that is only supported by a jack. The jack may slip or fail, resulting in serious injury or death.