Short answer is down the drivers side gunwale into the bilge area.
Start by taking the main engine throttle assembly loose from the boat and pulling it inside of the boat. There are like 8-10 screws and then you’re going to have to wiggle the throttle assembly out to allow room for your hand in that space.
I use skinny fiberglass wire push rods (link below) to thread through the space. Put 2 of those together, and tape them together. If you don’t tape them together and one comes apart, there will be some working words.
Tape your wire(s) to the rod and crawl under the dash with a good light. Below the dash you will see the main wire harness come through the gunwale. Fish the rod through that hole. Now sit on the seat and stick your right hand in the throttle assembly hole and continue to feed/wiggle the fish rod with your left. Once you find it slowly start pushing/pulling the rods and wire through. The new wire will want to get hung up under the dash where the main harness is.
From the throttle back there will be space above the storage locker to feed through.
Once you get through the back of the storage locker, remove the jump seat storage bin, another 8-10 screws and you are in the bilge area.