Pic 8 is of the wood being cleaned, blemishes bogged, sanded and then I painted it black to hide any future marks/scrathes that may occur. Th ewhite really highlighted scratches before.
Next pic is of the decal being applied, via windex on the sticky side of the decal and on the headbox wood itself, so both surfaces are nice and slippery. You have enough time to position the decal as desired and then squigee the windex between the headbox and decal (not too hard to avoid moving the decal and maybe squeezing out any gum)
Let it dry for say 10-15 minutes before trimming (pic 9) with a new, sharp knife. I actually cut a fair wack of the white part on top off to avoid the decal curling and folding over before letting it dry a little. I cut with the knife at an angle and use the actual headbox edge as a guide. Pic 10 is it fully trimmed.