To install a barn door, attach the rollers to the top and bottom edges of the door and affix the top and bottom trolley tracks over the barn door's opening and along the barn's floor, respectively. Finally, slide the door's rollers into the tracks and cap the track's ends.
To attach the barn door's rollers, first line them up against the door's top edge and mark the holes in the rollers' base on the door. Do the same for the door's bottom edge. Drill the marked holes and affix the rollers using 2-inch, heavy-duty wood screws or bolts.
Now measure the barn door height along with the rollers, and mark it on the top opening of the barn door while measuring from the bottom. Line up the trolley track along this mark, and mark the mounting holes on the track on the barn. Drill the holes, ensuring that there is a hole every 2 feet. Attach the top trolley track to the barn using 1/4-inch bolts. Attach the bottom track similarly along the barn's floor.
Next, position the barn door vertically next to one end of the trolley track. Then, lift and gently slide the bottom and top rollers simultaneously into the bottom and top tracks. Slide the door along the tracks into the desired position. Finally, cap the ends of the trolley tracks using 1/4-inch bolts over a 1-by-1-inch block of wood.