Spray-paint or otherwise mark the planned location of the bender board on the lawn.
Soak the bender board in water for several hours or overnight to make it pliable if it will be forced to make tight curves.
Dig a trench slightly deeper than the height of the bender board and about 6 inches wide.
Pound wooden stakes into the trench every 18 inches. Drive each stake deep enough so the top of the stake will be at least 1 inch below the planned top of adjacent soil or aggregate. This may only be necessary if the bender board did not come with stakes. Some commercially available bender boards are sold with stakes to be installed at the same time or after the board is placed.
Hold the bender board to the stakes at the desired height and pound nails through the board into the stakes. Begin at one end of the edging and use the level to make sure the edging remains level. Rust-resistant screws can be used as an alternative to nails for added stability.
Pound an additional stake into the trench whenever a section of edging ends and a new segment is placed. Attach the end of each section of board to the stake.
Cut the last section of edging to be installed to the correct length before it is placed into the ground.
Back-fill the trench, compact the ground next to the bender board and landscape as desired.