The house I am in has a fireplace that was originally wood burning, then turned into a gas fire place. What would be required to change it back?
First check to see if the damper is still there (the door at the top to close the chimney) I would also have the stack inspected & cleaned by a professional . If the top 2 things are good the gas line will need to be removed and the hole filled with fireplace mortar. Put a grate and doors/fire screen on and enjoy the fire .
you will have to remove the gas unit and gas line. then have the existing firebox and damper inspected for soundness. then you have to have the flue inspected, repaired and WETT tested (insurance makes this mandatory in ontario, but could be different where you are). then you will need a new cap (for wood - not the same as gas), maybe a new set of doors or a new insert, and then you should be good to go.