Chisel away the brick fireplace surround with a demolition hammer that has a chisel bit installed. Break away the mortar between bricks whenever possible, then remove individual bricks or chunks of brick by hand. Begin near the top of the brick surround and work downward to avoid a collapse.
Cut away bricks that are difficult to access with the demolition hammer using a masonry saw. Work from top to bottom until the brick is gone and the fireplace insert is visible.
Remove any bolts that hold the fireplace insert into the surrounding walls using a socket and driver. Detach the fireplace door and remove any visible mounting brackets using the appropriate sockets.
Sweep away masonry chips and dust as you work with a hand broom and dust pan. Check for loose bricks before hammering since they may become dislodged when the bricks around them are removed.
Insert one or more pry bars into the gap between the fireplace insert and the concrete foundation or masonry walls. Pry slowly to loosen the insert before removing it completely. Pry away the thin metal flue, which is the duct that attaches to the top of the fireplace insert to allow smoke into the chimney.