Rega modification

Can anyone tell me the best way to install a 5-pin DIN into the base of a Rega RB 300 tonearm?
This is not a normal fit-up. What kind of preamp are you hooking this up to?
My phono preamp is the Lehmann Audio "Black Cube." The Rega RB 300 arm is mounted onto a Thorens TD 3001 BC suspended turntable. The cartridge is a medium low-output MC (the Goldring Eroica LX with output at O.5 mV at 100 Ohm). Because of the low voltage signals that flow through them, I think it is important that unnecessary resistance be removed from the signal path and that the quality of the cabling in the tonearm and the turntable cable be the highest quality possible. I want to modify the Rega RB 300 to allow me to change the stock Rega tone-arm wires and phono cable to higher quality "Ortofon BN-TAC 1 Super Pure Copper" tonearm wires and Cardas Golden Cross PH cable. I was recently inquiring about purchasing a Cardas Golden Cross PH phono cable with their firm-specific 5 pole DN plug at a high end dealer. The salesman asked me what tonearm I was going to mount it on. I said: Rega RB 300. He said that it was impossible to use the Cardas with the Rega because the factory-mounted RCA cable in the Rega is not removable. I was devastated. I went home and opened up the Thorens to see that the salesman was right about the Rega: the thin grey plastic-coated RCA cable fits right into the end of the tonearm. I removed the cable only by loosening a little hex nut on the outside of the threaded tonearm pillar. Inside I found the four wires of the cable terminated on a little plastic circlular plate where the ends of the inner tone arm cables were soldered. The salesman mentioned a company (Incognito) who can replace the inner tone arm wire and the cable with a single wire. This seemed to me quite a good idea. However, I want to be able to select the cable that I use with my Rega and to also change it if I want. Thus the idea of inserting a Cardas standard 5 pin DN female plug came to me. However, I have no experience with this type of modification. How does one remove the old inner tonearm wires? How does one insert the new tonearm wires? Where do I terminate these wires? Where can I find a 5 pin DN female plug that has the right diameter to fit into the base of the Rega? How do I terminate the inner tonearm wires on the female plug? Will the phono cable have enough clearance below the tonearm pillar to allow my Thorens arm mounting board to move freely? Is all this work worth it? Considering that the RB 300 is the most widely used OFM 'arm on the market (used on many turntables by other manufacturers) I have no doubt that there are hundred of Rega owners who have never realized the potential of their turntable because of the cheap RCA output cables fixed onto their tonearms. They have used the stock-mounted cable from the day they bought it. Even perhaps with low-output MC cartridges. That seems a big mistake.
Turn around and put the wire outside the arm tube. See a picture here:
Thank you Abc. Your reference to the hotrod phono page was very useful and to-the-point. It made me aware of yet another possibility for wiring the cartridge to the phono preamp--namely, OUTSIDE the tonearm. I also like the advice the author gives about not using heavy WBT or CARDAS plugs on phono source cables. I wish there was a technical explanation for this: the author confesses he does not know the reason cheap plastic Radio Shack plugs sound better than heavier plugs here. I also wish REGA left a hole in their tonarm around the pivot so that I would not have to tape or shrink wrap the tonearm cables to the tonearm. I am a little worried about mechanical interference with this solution. Maybe I will drill my own hole in the tonearm and route the cables out from there--like on the Simon Yorke S9 design tonearm.