1.Measure your window to determine the rod length. For most windows, it looks best when the rod extends 2 to 4 inches past the window frame on each side. 2.Purchase a dowel rod at a hardware store. Choose a diameter based on your finials. Excluding any finial lip, measure the diameter of the finial base. Make sure your dowel rod diameter isn`t larger than the finial measurement and no more than 1/4" smaller. 3.Mark your length with a pencil and cut your wooden dowel to size with a hacksaw. Sand the sawed end of the dowel rod with medium-grit sandpaper until smooth. 4.Drill finial holes on each end of your dowel. Choose a bit size based on the screw ends protruding from the base of your finials. Should your finials not have screws, purchase two dowel screws--double-ended wood screws--and drill holes in the ends of the rods and finials. 5.Paint or stain the dowel rod and let it dry. Paint or stain your brackets and finials too, if needed. 6.Install your brackets according to the manufacturer`s instructions. Slide any rings or rod-pocket curtains onto your rod and mount the rod on the brackets. Screw your finials clockwise into the holes you drilled on the ends of your rod.