Vacuum and dust the stairs before proceeding.
Measure the width and depth of each stair. Choose an Oriental carpet tread that is smaller than the width by a few inches and smaller than the depth by one to two inches.
Place one of the carpet treads on the top stair so that it is centered. There should be equal amounts of visible bare wood on each side of the tread. Behind and in front of the tread there should be equal amounts of visible wood.
Make a light chalk mark on each side of the tread on the stair wood to mark the position.
Cut strips of two sided carpet tape about one inch shorter than the length of each strip. Cut two more strips of the tape about one inch shorter than the width of each strip.
Remove the backing off one side of each two sided strip. Affix one strip to the underside of each long end of each carpet tread. Affix one strip to the underside of each short end of each carpet tread. There will be four strips on each tread.
Remove the other side of the backing and carefully position the carpet tread on the stair so that it is completely centered.
Press firmly on the carpet tread to affix it to the stair. Smooth out the tread with your hands and verify it is securely attached,
Repeat for each additional stair.