My sugestion would be to use the coverstrip as a guide and you will see how much to cut and if your shins flare out att the top like mine, cutting 10 from the ridge would make it difficult to assemble (see pic)..mark the middle of the strip, hold it to the shin to were it sits right and then transfer the mark to the shin, I learned this from Troopermaster, check his FB page and you will find lots of helpful stuff