The first step is to install all the tackless on the riser. By doing this, you will get the most difficult part out of the way, as well as avoiding tearing your hands on the tread piece of tackless.
Achieving the proper space from the tread can be a little tricky at first. To make a spacer, cut two, 2-inch pieces of tackless, turning the pins to face each other, and tap them together. This provides a block on which to rest the riser piece of strip while hammering, as well as providing the proper spacing from the tread (Photo 1). Install the tackless with the pins angled, pointing toward the tread. It is better to adjust the tread piece of strip to account for carpet thickness.
The tread piece of tackless is where you adjust for the thickness of the carpet. The proper gap between the tread and riser strips should be double the thickness of the carpet being installed, plus the thickness of your stair tool (Photo 3). Remember, do the risers first and save your knuckles. When cutting the stairs, install a strip on each side of the tread, leaving it ¼-inch short of the nose to avoid a sharp edge.
A 2-foot-9-inch-by-6-foot piece provides six stair pads. Lay the stair pads on the stairs. Starting at the top and working down, staple the tread first, then the nose (Photo 4). Installing the pads from the top down is faster and less aggravating; you avoid hitting the loose pad on the upper step while stapling.
Lay out the stair run, starting with the bottom stair. Secure the edge of the carpet to the strip. If there is carpet meeting it from a landing or the lower floor, leave a couple of extra inches and chisel it into the gap between the tackless with a mallet and stair tool. If meeting a finished surface such wood or tile, the riser strip should be ¼-inch from the floor. Leaving enough extra space for a tuck (¼-inch), secure the strip. In some cases, it is necessary to carefully part the naps and bury a couple of staples to help lock the starting edge to the strip.
After you have completed stretching the last stair, trim and tuck it to finish just like you would a wall.