Have some Polyfila a ready for the room inside if you get it wrong
Overhang doesn't matter, above suggested your drilling in the wall one course down 45angle , depends on how your house is made up , some have the inner wall in the way and you have to feel quite far down where the cable is , just shove loads of cable in from outside and if you don't have rods use a metal coat hanger as a hook to poke in from inside the roof to the eaves to find cable