After the new carpet on the stairs was installed, it was up to me to add the transition strips to complete the project. After a lot of thinking on how best to get the tightest seam, I decided to cut the track to the width I needed, cut 1-foot pieces of T-moulding and end-molding, and pushed them on the middle of the track. I then pushed that firmly against the carpet and marked the holes with a Sharpie. I drilled the pilot holes and screwed down the track, as seen in the first picture below. I cut the molding to the proper width and pushed them into the track, shown in the second picture. Totally happy with how it turned out.