Immobilize it with a doorstop and plane it in place see step 3.
Plane hinge side of door.
Step 2 use your ruler to measure 1 8 inch from the jamb to the start and end points on the door.
The hinge master mortising jigs have been designed to route most of the various hinge sizes of todays door industry.
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.
The radius of the mortise is determined.
A hinge can often work loose binding the door against the frame.
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.
Use a pencil to mark this area on the side of the door not on the edge.
People usually try to plane off the edge.
But frequently the solution is on the hinge side.
Turn the door so.
That may be difficult on older painted doors.
Plane the hinge or lock sides of the door in the same direction as the wood grain applying light pressure to remove very small amounts of wood at a time.
Test each screw by tightening it with a screwdriver.
But for maximum control and to plane longer portions take the door off its hinges with a screwdriver or drill.
On many doors the grain runs from top to bottom instead of side to side.