In the event you don't yet have a runner, you're welcome to order one custom woven for your dollhouse. There are a few styles shown in the Showcase, or we can create one specially for your decor.
Installing stair runners
None of this is brain surgery, but do read the instructions all the way through before beginning.
If possible, remove staircase from house, or install runner before installing staircase.
Lay the runner on the staircase, centering between wall and edge of balusters, or whatever looks balanced. Using an awl or other sharp pointed tool, make pilot holes in the tread, at both edges of the runner, way back where the tread meets the riser. (See Figure A) A cardboard jig, cut to fit the stair width, and marked for the holes is helpful.
Remove the runner, and using a small drill bit, 1/32" or so, drill into the tread. If your staircase is solid wood, drill in about ½", if the space under the treads is open, just go all the way through. Check to make sure the holes will accommodate the rod holders' stems.
Insert the rod holders into the holes you drilled. If the staircase is solid wood, first trim the "stems" to 3/8" then put a drop of super glue on the stem and insert into hole. If the staircase is open underneath, simply bending the stem to the side will secure it in the hole. The eye should be flush with the tread, and at right angles to the riser.
Make a ¼" casing at the top end of the runner. This can be done by stitching with matching or "invisible" thread, or by gluing along the cut edge with tacky glue. If gluing, put one of the rods inside the casing before gluing, so it is sure to fit.
Starting at the top of the staircase, slide the rod through the casing, insert one end of the rod through the eye of the holder, then slide the rod sideways so it will go through the eye on the other side.
Work down the staircase, smoothing the runner over the next tread and inserting rods as you go. At the bottom, the runner can end just under the lip of the last tread, or at the base of the last riser, next to the floor. (See Figure B) Allow about 3/8" for the casing, and either run a line of stitching or a bead of glue (let dry) and then cut on the waste side of the line.
Stitch or glue the runner around the last rod, and insert as you did the top one.
The leftover runner can be made into a throw rug by stitching or gluing ¼" from the edges, and raveling the ends to make fringe. The pre-stitched end will have to be trimmed off, of course. You did it! Congratulations, good job.