1. Installation Instructions for Interior Wood Doors 1 Prepare the rough opening a Are the walls straight b Are the uprights level c Is the subfloor clean dry level and solid Put fasteners in jambs just above the hinge positions on the hinge jamb Leave fasteners sticking out a little On hinge jamb only place one shim behind each hinge between the hinge jamb and the wall stud Check hinge jamb for plumb and true with a 6 foot level Drive a fastener through each shim and remove excess shim Shim between the strike side jamb and wall stud near the top and bottom of the jam across from the top and bottom hinge locations Adjust the frame so it is flush with the face of the door Drive fasteners through jambs at locations of top and bottom shims and remove excess shims