It's very simple actually. Unfortunately I used all my wire, so I really can't show you step-by-step instructions using pictures. I'll do the best I can just explaining it. It really is incredibly simple. Sorry if I give way too much detail here.
Here's the cable I used:
http://www.radioshack.com/product.as...Fid=910%2D1621
It's not actually a cat 5 cable, but it worked fine regardless. It's a Belden shielded cable containing only 3 twisted pairs vs. the 4 pairs that a cat 5 cable uses. I picked it up from a local RadioShack.com store here in Atlanta. I also purchased 6 RCA phono type connectors.
Pick up a soldering iron with a small head. RadioShack.com had one for about $10. Get a roll of 60-40 resin flux core. Thin 0.75mm diameter.
Remove about 2 or 3 inches of the plastic sheathing of the wire. Carefully peal back the wire mesh (this is what I refer to as the shield wire) to expose the other wires. In case of the wire I used, besides the wire mesh, there is also another separate shield wire that will be exposed once the mesh is pulled back, resting against the foil. This separate shield wire is like the other wires, but lacks plastic sheathing and makes contact with the wire mess. You could form a similar wire using part of the mess wires if necessary. Cut away the mess if you have this separate shield wire, if not cut away the excess mess wire that you didn't use to form a separate wire.
Peel back the metal foil and cut it away. Cut away the insulating fibers as well (not sure of the technical terms for these, but you'll know what I mean).
What you should end up with (if using the 3 pair wire I used) is 7 wires (3 pairs and the shield wire). Strip the sheathing off the tip of these wires with your finger nails. Remove just enough of the sheathing to expose just the tip of the wire. All you want is enough exposed to slip into one of the solder holes on the RCA connector and bend it over. If you remove too much, the exposed wires may be able to touch after soldering to the RCA connector and cause a short. If you remove a little much sheathing, simply cut a little off the tip of the wire.
The RCA connectors will have two solder points, one that is attached to the "prong" part of the plug and the other the "outer sleeve". Again, forgive my terms here.
First build the Y (green) connector, since it's a little unique from the others.
Remove the plastic or metal screw on shield from the RCA connector. Untwist the green-white wire (green with white stripes or spots) from the white-green wire (white with green stripes or spots). Cut away the white-green wire You won't need it. Instead, we'll use the shield ground wire.
Slip the plastic or metal shield over the shield ground and the green-white wire, so that we can attach it to the RCA connector after soldering. Rest the RCA connector in something to hold it steady while soldering. I used a pair of vice grips, but be careful to only use light pressure or you'll damage the connector.
Slip the end of the green-white wire into the prong's solder hole of RCA connector and bend it over. Hold the wire slightly taunt to keep in place. Use the same hand to control the solder. Use the soldering iron with the other hand. Press the soldering iron against the wire and the connector. Press the "thread" (?) of solder to the same point. Continue "feeding" solder until it forms a good connection. Without releasing the wire, pull the iron away and blow on the solder point until it cools slightly. This whole process should not take more than a few seconds.
Solder the shield wire to the RCA connector's sleeve in a similar fashion.
Solder the red-white to the prong and white-red wires to the sleeve of another RCA connector. Solder the blue-white and white-blue wire to another RCA connector. Repeat this whole process for the other end of the wire. The important thing about the colors here is to be consistent on both ends of the wire.