The basic principle of course is to relocate a game cart port with wires so the game cartridge can be horizontally mounted or located into a more convenient place on a portable.
What you need is quite simple - thin wires, the more flexible the better, and preferably at least three colours of wires; solder, wire strippers and soldering iron; useful to have some desoldering braid to hand just in case too.
Why at least three colours of wires you ask - simple, when you've done the wiring, if a wire was to be loose, or if you want to check you've wired the port correctly, it is easy to think "it's the white wire between the blue and red one" rather than having to trace a wire back to location. The reason for flexible wires is simply that you'll have 48 wires to relocate on an N64 game port, if the wires are not flexible you'll break solder joints or bend pins or simply just have a harder job getting the wires where you want them afterwards.
One important thing is to be methodical, and carefully. To date, i've not had an issue with doing this sort of relocation work, always works.
The principles of tinning connections is to give a better solder joint and in the case of wires, stops strands in the wires becoming loose and causing shorts; also makes it far easier to solder to pins without issue of damaging things by having the soldering iron making contact for too long (metal is conductive in heat, to other components after all).
So, firstly, tin the pins on the game port by putting solder onto the soldering iron and then quickly stroking the solder from the iron onto the pins in turn.
Then cut wires to required length; under 7" or you'll find the game cartridge might not work due to interference on the lines. I've used 6.5" which is fine.
Tin the solder joints you're connecting the wires to on the motherboard, this will greatly reduce the chance of wires breaking loose due to bad solder joints later.
Then comes the fun! Wire methodically, one way across to the other, one layer at a time.
Then turn the motherboard around and you'll notice it is then just as easy to wire up the other side of the game port and to the motherboard.
Done.
That wasn't hard, right?
