Run a piece of thin cardboard or folded paper in between the door and the jamb to identify the start and end point for the area that needs to be planed.
Plane hinge side of door.
Running the plane in this direction will create smooth cuts instead of chunky bumpy cuts.
People usually try to plane off the edge.
Test each screw by tightening it with a screwdriver.
A hinge can often work loose binding the door against the frame.
But for maximum control and to plane longer portions take the door off its hinges with a screwdriver or drill.
Step 2 use your ruler to measure 1 8 inch from the jamb to the start and end points on the door.
On many doors the grain runs from top to bottom instead of side to side.
The radius of the mortise is determined.
Before trying to trim the door open it and examine the hinges.
Complete one pass per stroke with a hand or power planer with.
But frequently the solution is on the hinge side.
That may be difficult on older painted doors.
Use a pencil to mark this area on the side of the door not on the edge.
Turn the door so.
Hold a belt sander plane or power plane at about a 45 degree angle to the edge of the door and remove material to the witness line.