There is often a need to change the existing wiring in an older building. Sometimes the wiring wasn't completed all at once, and different kinds of cable may be running throughout the building. Almost all wiring is now done with eight-strand twisted pair, which can be used for both telephones and computer networks. However, there is still plenty of four-strand telephone wiring in older homes and buildings. Because the colour-coding is different, you need to know how the two cables should be joined.
Cut away approximately 2 inches of the sheath around each wire using the cutting tool. Be careful not to nick the wire insulation. You can cut away more if you find the 2-inch pieces difficult to work with. Separate the strands in the four-strand wire, and separate the pairs in the eight-strand twisted pair wire.
Identify the first and second lines on the four-strand wire. The first line is the red and green pair. The green wire is called the "tip" wire, and the red wire is called the "ring" side. Yellow and black is the second pair. Black is the "tip" wire, and yellow is the "ring."
Pull out the first and second pairs from the eight-strand wire. The first pair in the eight-strand wire is the blue and white pair. The second pair is orange and white. Tip and ring are identified in the following manner: the wire that is mostly white in both pairs, called white/blue or white/orange, is the "tip" side. The wire that is darker in colour is the "ring" side, blue/white or orange/white. Untwist the two pairs just so they're long enough to fit all the way into the telephone-wire splice connectors.
Take the tip side from the first pair of both cables -- green from the four strand wire and white/blue of the eight strand wire -- and insert them all the way into one of the splice connectors. Do not strip the insulation off the wires. Using the regular pliers, open wide to ensure a level crimp and clamp down on the button of the splice connector.
Repeat step four with the remaining three wires: red to blue/white, black to white/orange and yellow to orange/white.