How to Replace Doors in a House?

Replacing doors in a house involves several steps, from removing the old door to installing the new one. Here's a comprehensive guide:

1. Preparation & Safety

Gather your tools: You'll need a screwdriver (or drill with screwdriver bits), hammer, wood chisel, measuring tape, level, pencil, safety glasses, and possibly a pry bar. A circular saw, miter saw, or hand saw might be required depending on if you need to trim the new door. Consider shims for adjustments.
Safety first: Wear safety glasses throughout the process to protect your eyes.

Detach the door from the frame: Use a screwdriver or drill to remove the screws from the hinges, starting with the bottom hinge first to prevent the door from falling suddenly. Have someone assist you for heavier doors.
Remove the old door frame (optional): If you're replacing the entire door and frame (pre-hung door), carefully use a pry bar to remove the old frame. Score the paint around the frame with a utility knife first to prevent damaging the surrounding wall. Remove nails and screws.

This step varies significantly depending on whether you purchased a pre-hung door or just a door slab.

Prepare the opening: Ensure the rough opening is square, plumb, and level. Remove any debris or obstructions.
Insert the pre-hung door: Carefully position the new door and frame into the opening.
Shim and secure the frame: Use shims to level and plumb the frame within the opening. Insert shims behind the hinge locations and the strike plate area. Secure the frame to the wall studs using screws.

Measure and cut the new door: Measure the height and width of the old door (or the door opening) and transfer those measurements to the new door slab. Use a circular saw, miter saw, or hand saw to trim the new door to the correct size. Be precise with your measurements.
Locate and cut mortises for hinges: Place the old door on top of the new door and trace the hinge locations. Use a chisel and hammer to carefully cut mortises (recesses) for the hinges on the new door. The mortise depth should match the thickness of the hinge. You may also need to create mortises on the door frame if replacing hinges.
Prepare for the lockset: Mark the location for the doorknob and latch on the new door. Use a hole saw and chisel to create the necessary openings for the lockset hardware.

Install the hinges: Attach the hinges to the door and the door frame using screws.
Hang the door: Carefully lift the door and align the hinges with the hinges on the door frame. Insert the hinge pins to secure the door.
Test the door swing: Open and close the door to ensure it swings smoothly without binding or sticking. Adjust shims if necessary.

Install the lockset: Install the doorknob, latch, and strike plate according to the manufacturer's instructions.
Install the strike plate: Chisel out space for the strike plate and install it.
Caulk and paint/stain: Apply caulk around the door frame to seal any gaps. Paint or stain the door to match your desired aesthetic.

Fine-tune the door: Make any necessary adjustments to the hinges, latch, or strike plate to ensure the door closes properly and latches securely.
Clean up: Remove any debris and dispose of materials properly.