Lighting, Light Fixtures, Ceiling and Exhaust Fans - Wiring a light switch on an exterior wall

I'm planning on wiring a new circuit for recessed lighting in a living room that currently has no lighting or available switches to run off of. The ceiling above has an attic so running the lines for the housings is not a problem. The problem is running the line to the switch. I want to do this the cleanest way possible - having the least sheet-rock repair after. The wall where I'm installing the switch is an exterior wall so the attic space above this wall is quite minimal as the roof slopes down to this wall. I don't think there's enough access in the attic where I can drill a hole into the wall cavity from the attic to snake the wire down to the switch. Any ideas on how I could do this without opening up too many holes in sheet-rock that I'll have to repair?

Could you open the sofit on the outside and use an angle drill into the top plate? If not then a hole at the top of the wall should allow you to fish up into the attic and down to the switch.

We have to drill holes in top plates to attic spaces to install switches often. You will have a hole about 5/8" by 2 or 3" down, but it is easily repairable with sheetrock compound and a patch. Since it is an exterior wall, it would be best for you to check for a perlin in the middle of the vertical run. These are used as firestops, and it will be impenetrable without doing more wall work, or installing the old work box over the perlin.