Gather tools and materials: replacement threshold, tape measure, screwdriver, pry bar, utility knife, drill, caulk, sealant, screws, shims, hammer
Open the door and secure it if needed
Remove the door sweep or weatherstripping attached to the threshold
Unscrew the existing threshold
Cut any paint or caulk along the edges with a utility knife
Pry up the old threshold carefully
Remove old caulk, debris, and fasteners from the doorway
Measure the opening and cut the new threshold to fit if necessary
Dry-fit the new threshold in place
Check the fit against the door bottom and side jambs
Add shims under the threshold if needed for proper height and slope
Apply a bead of caulk or sealant where the threshold will sit
Set the new threshold in place
Fasten the threshold with screws through the predrilled holes
Reinstall or adjust the door sweep or weatherstripping
Test the door for smooth closing and proper seal
Apply exterior-grade caulk around the edges if needed
Clean up excess sealant and debris