We have some info in the FAQ's but still need to add it to the manual - sorry.
The swivels and rod end supports are inserted 1/2" into the legs before welding so drill your holes top and bottom of the leg at 1" from the weld line.
I use soldering wire dropped in at the top then use hemostats (ok, from my younger days) to pull it out at the bottom. Then tape the speaker wire to the soldering wire and pull it up and through. There are many other ways as well.
The transition from the bottom of the tower to inside the boat is the harder part. There are lots of connector / gromet options at Radio Shack, Home Depot and others. Also, there are some links at www.diyTower.com
to Waytek Wire and a great guide.
Love to see some pictures of what others use to bring the wires into the boat from the tower.
Feel free to call. 877-77-Tower