Measure the size of the gable vent. Mark the measurements on the inside wall. Allow 1/4 inch on all sides for clearance. Construct a frame between two studs the size of the vent using 2-by-4 lumber, using the measurements as a guide. Attach the cut pieces to the wall with the drill and screws. Drill holes through the wall at each inside corner of the vent frame to mark the location of the cut.
Go to the outside of the house. Locate the drill holes. Line the straight edge from corner to corner using the drilled holes as start and end points. Trace an outline for the vent opening. Cut out the opening along the lines with the skill saw.
Cut and install building paper around the vent opening for flashing. Staple the building paper in place. Apply a bead of caulk around the building paper with the caulking gun. Install the metal flashing that came with the kit over the building paper.
Apply a generous bead of caulk under the vent flange. Mount the vent into the vent hole. Push the vent firmly into place. Secure the vent to the wall by attaching a screw at each corner using the drill. Apply a bead of caulk around the edge of the vent flange.