Jerry, I used big finishing nails in predrilled holes down from the top. I put 2 in each side and 3 into the riser. Several factors were involved in this. I pre-finished my treads which made it much easier. I used Minwax colored wax wood filler to fill the set nail holes. There was no access from the bottom, so screws were not possible. I'm sure that there are other approaches for this depending on your particular situation.