The thresholds are integrated into the jambs. I wouldn't bother replacing the part. If the wood insert is too low to make contact with the door weatherstripping, cut a thicker piece and nail it in place.I am attempting to fix my threshold. I removed the wooden adjustment strip. A couple of the srews are stripped. Can the "anchors" be repaired(replaced)that hold the strip into the bottom woodedn piece? Or does the entire threshold need to be replaced?