I ran cables for a bow thruster all the way from the forward cabin to the Helm without removing any of the headliner. From the Nav Station run the cables down under the removable panel on the bulkhead under the Nav Station, then thru the underfloor compartment. Continue to run the cables under the floor and then under the aft bed. In the center under the aft bed there is an opening under the aft bulkhead to run the wires up to the Helm. The hard part is getting the wires thru the stainless steel tubing at the helm, a very tight fit.
PM me if you want to discuss.
Andy