Depends on how straight a run it is. A small formed brass tube would give you conduit to route the control string.
The problem I see is not so much pulling them up, but letting them back down. You'll get enough force to pull them up using a string housed in a tube (think steering cable); going down, though, you need enough weight at the other end to pull things back down (which can be considerable.)
Hmmm. Perhaps a cable between the transom and the console, with string on a short run through the transom to the trunks?
I can also see something along the lines of a remote spotlight: wireless control of a small electric motor.
jky