Cut the transition bar with a hacksaw equipped with a metal-cutting blade to fit the length of the joint.
Lay the transition bar into position at the joint underneath the edge of the carpet.
Screw the bar to the flooring, using galvanized screws.
Place a straightedge on the carpet 1/4 inch from the transition bar. Cut the carpet with a utility knife, using the straightedge as a guide.
Stretch the carpet with a knee-kicker so the carpet edge reaches the transition bar. Use a stair chisel to slide the edge of the carpet underneath the transition bar and hook the underside of the carpet onto the pins inside the bar.
Bend the flange of the transition bar onto the carpet by laying a wooden block over top and tapping it with a hammer.