Though it may seem intimidating, removing a door frame from a brick building is relatively easy. The frame is connected to the wall on either side with anchors or fasteners. These anchors are then covered with trim or casing to enhance the visual appeal of the opening. Whether your frame is made of steel or wood, you'll find that this task can be completed in just a few hours using simple tools and techniques.
Use a hammer to drive out the hinge pins. This will allow you to remove the door from the frame, which will make it easier to remove the frame from the opening. Some exterior doors may have hinges with non-removable pins. If your door has these hinges, use a drill or screwdriver to remove the hinges from the frame entirely, then set the door aside for reuse or disposal.
Cut away caulk around the perimeter of the frame using a utility knife. Repeat this process on both the interior and exterior sides of the opening, if applicable.
Gently pry away trim or casing from around the door. Use the claw end of the hammer to remove this trim. Remove any remaining nails, and set the trim aside for reuse.
Examine the frame. Some frames in brick walls may be butted up to the wall, while others are wrapped around. If your frame is wrapped around the wall you'll need to use a pry bar to pull the bottom of the frame away from the wall slightly. This will allow you to access the fasteners so you can remove the frame.
Slide a reciprocating saw (sawzall) blade into the gap between the frame and the wall. Start at the bottom of the opening, and work your way up the wall, cutting away anchors or fasteners holding the frame in place. This will take longer with a wrapped frame, as you'll have to pry the frame off the wall a bit at a time as you proceed up the wall.
Remove the frame from the opening by tilting the top of the unit down toward the floor once all fasteners are removed. If you are still unable to remove the frame once the fasteners are cut away, try cutting the frame at the top of each jamb where it connects to the header. This should allow you to remove the two jambs. If the header is still stuck, try repeating Step 5 to look for fasteners along the header.
Always wear eye protection when operating power tools.