Print them out as an edible image, cut with xacto knife and stick on?
You can also cut the chevrons, stick them to a strip of waxed paper (cut to the height of your cake) with crisco, brush crisco on the side not stuck to the paper, and transfer to the cake that way. Make sure they are well stuck to the cake using a smoother, and carefully peel the paper away. I did it the other day for horizontal stripes and used parchment paper, it worked great. You can still jiggle them around on the paper to get things perfectly lined up before transferring to the cake.