If you approach removing your fireplace surround like an ordinary demolition job, you'll needlessly damage the surrounding walls. If work strategically, however, and use the minimum amount of force required to remove the fireplace surround, you can get it done without damaging the walls. No matter how solid your fireplace surround is, it will come away from the wall in one piece with surprisingly little physical effort on your part.
Things You'll Need
Electronic stud finder
Run the blade of a utility knife along the seam where the fireplace surround meets the wall, along both sides and the top.
Locate the studs in the wall with an electronic stud finder. Place sticky notes on the wall where the studs are.
Attach cardboard to the wall directly above the fireplace surround with masking tape. This will protect the wall from damage as you work. Transfer the sticky notes to the cardboard, if necessary.
Wrap the end of your flat bar with masking tape. This will keep the flat bar from damaging the wall.
Slip the flat bar between the top of the fireplace surround and the wall where a stud is located. Hit the free end of the flat bar to pry the fireplace surround from the wall. Repeat for the other studs across the top of the fireplace surround.
Carefully move the fireplace surround away from the wall.