Travis -
Generally you can run a push/pull rod out the bottom of the cowl either in the cooling air outlet or next to it. You may have to use a bellcrank to get the linkage where you want it. Since you spoke of going thru the side of the cowl, I presume the motion is sideways. A 90 degree bellcrank (easily made from a cruciform/cross shaped servo arm). will translate sideways motion to up and down motion by cutting off two of the arms and keeping two arms that are perpendicular to each other.