How to Install a Deadbolt

Typical Tools and Materials List

Wood chisel (3/4-inch)
Hammer
Torpedo level
Carpenter's square
Adjustable hole saw bit (or appropriate size)
7/8-inch spade or Forstner bit (or appropriate size)
1/8- and 3/16-inch drill bits
Electric drill
Tape measure
Pliers
Awl
Phillips-head screwdriver
Drill guide (optional)
Utility knife
Masking tape
Internal deadbolt

For maximum effectiveness, deadbolts should be installed 10-12 inches above, or at least 6 inches below, the existing lock. Make sure that your deadbolt placement will not interfere with screen or storm door handles.
Your deadbolt will include a template for installation placement. Tape the template to the door, following the manufacturer's instruction. Check the placement with a square and level to make sure it is straight on the door.
Locate and mark the pilot hole position for the screws with an awl. Also mark the center of the cylinder hole on the door face, and the bolthole on the door's edge.
Using a 1/8" bit, drill the pilot holes for the screws about 3/4" deep. Use care to keep the drill level. Then, using an adjustable hole saw set at the appropriate size for the cylinder hole (consult manufacturer's instructions), begin drilling the cylinder hole through the door face. Use the center punch mark as the pilot hole, and drill as straight as possible until the pilot bit protrudes from the far side of the door. To prevent splintering the wood, finish drilling the hole from the other side.
Next, use a 7/8 (or appropriate size) spade or Forstner bit to drill the hole for the bolt through the edge of the door. Hold the drill level, and drill straight through to the center of the cylinder hole. Then continue drilling into the far side of the cylinder hole about 3/8".
Insert the latch bolt into the bolthole. To recess the latch plate and make it flush with the edge of the door, score around the latch plate with a utility knife. Remove the bolt assembly and use a chisel to shave away thin layers of the wood to the depth of the plate. Trail-fit the bolt assembly until the latch plate recess hole is complete. If you cut too deeply, you can shim behind the latch plate to bring it up flush with the door's edge.
Install the bolt assembly to the doors edge with the provided screws. Insert the cylinder into the hole on the outside face of the door, sliding the connecting bar through the slot in the bolt latch. The bar will extend to the inside of the door.
Install the thumb latch assembly to the inside of the door, aligning it with the connecting bar. Secure the assembly with the mounting screws. Check to make sure that the bolt projects and retracts easily.
Turn the thumb latch to project the bolt. Then, hold the door closed against the door frame. Trace the position of the bolt onto the doorframe. Using a square and level to continue the marks around the inside edge of the doorjamb. Measure and mark the center point where the bolt will strike the jamb.
Prepare the hole in the doorjamb where the latch bolt will project. Some locks will require only a drilled hole, while others will require an elongated, square-edged hole be chiseled to accept a metal strike box.
Align the strike plate on the doorjamb and mark around it with the utility knife. Chisel out enough wood to allow the strike plate and box to fit into the jamb with its face flush with the surface of the jamb.
Install the strike plate and box. Mark pilot hole locations for the strike plate attachment screws. Drill the pilot holes with a 3/16" bit, then install 3" screws driven through the jamb and into the framing stud.
Test the operation of your new lock.