Dig out the soil to a depth of 8 inches from the area where you'll be putting in the walkway. Place the dirt in a wheelbarrow to haul it away.
Place a layer of landscape cloth on the bottom of the excavated area. Overlap separate pieces of cloth by several inches. The landscape cloth will inhibit the growth of weeds through the bottom of the walkway.
Place landscape edging strips along the lower edge of the walkway. The tops of the strips should be even with the ground at the top edges of the walkway.
Fill the bottom of the excavated area with gravel, filling it in to within 2 inches of the top.
Fill the remainder of the walkway with decomposed granite. Smooth the granite with a rake.