Climb into the attic and drill a reference hole up through the roof. Remove your drill bit and replace it with a 5-inch hole saw. Leave the attic.
Climb onto the roof and locate the reference hole. Center your hole saw over the reference hole and cut through the shingles and decking.
Place the vent over the hole and outline the edges on the roof. Cut along the outline with your utility knife and remove the shingles from inside the outline.
Attach a 4-inch metal duct connector to the vent cap. Pull back the shingles around the hole. Push the connector through the hole until the vent cap is against the roof. Nail the flange to the roof and apply roof cement to the nail heads. Press the shingles around the edge of the vent cap and apply roof cement to the seam between the vent and shingles. Climb off the roof.
Climb into the attic. Slip the end of the duct over the duct connector and secure it with a 4-inch hose clamp.