Important: To install the vents, holes will need to be cut into the soffit. When cutting the holes that will allow ventilation, it's critical to make certain that you don't cut into the roof rafters. Cutting the rafters could weaken the structure of the roof. Use a stud-finder to help determine where the rafters are located before cutting the vent holes. Visible nail or screw heads on the outer soffit surface or fascia boards may also give indication of rafter locations. Once the locations of the rafters are determined, use the vent itself as a template to establish the locations where you'll be cutting.Scribe a line around the outside of the vent, remember you'll need to cut a hole slightly smaller than the dimensions of the vent. Make the cuts about 3/4" inside the lines to incorporate an allowance around the edge into which the mounting screws will be secured.
The lower surface of the eaves will need to be cut into using a jigsaw or keyhole saw. Drill some holes in the wood soffit in order to insert the saw-blade and begin cutting. Use a cordless drill and a spade bit to drill the holes into the wood.