Assuming you know basic ini modding...
Attach this script:
Code:
function Update(self)
   if self:IsPlayerControlled() == false and self.AIMode == Actor.AIMODE_SENTRY then
   self:GetController():SetState(Controller.BODY_CROUCH,false);
   self:GetController():SetState(Controller.MOVE_RIGHT,false);
   self:GetController():SetState(Controller.MOVE_LEFT,false);
   end
end
to an actor. It'll only work on the actor that you attach the script to, though.