Turn off the gas at the tank outside your home or if you have natural gas piped in at the entrance valve. Turn the valve clockwise until you cannot turn it any further.
Remove the ceramic logs from the inside of the fireplace, cutting the gas line. Cap the line or twist over and crimp with pliers to close off the line.
Hire a chimney professional to inspect your chimney. Some homeowners stopped using their fireplaces because they were not constructed properly and you want to make sure the lining of the chimney is not cracked. At the same time, ask the chimney professional to inspect your firebox for sizing. If the opening is too large for the size chimney flue in your house, the draft will not pull the smoke out of the house properly. Line the floor of over-sized fireboxes with a layer of firebricks to reduce the size of the opening.
Insert a fireplace grate for holding the wood up and off the floor.
Add a glass door to the opening of the fireplace to prevent the loss of heat up the chimney. Follow the manufacturer's directions that came with your door to anchor the door to the hearth. Seal off the gaps around the edge by stuffing glass wool insulation into the gap around the back edge of the door. Slide the door into the opening and screw into the anchor holes on the hearth.