kitchen..unfortunatly, the wires are bare....now we bought the jack
and went to install it, and found that there are only three wires
coming out of the hole, red, green and yellow..no black,,,
how can we install this new jack to an old line that has only the
three colored wires?

Rip out the old wires altogether and put in a new modular wire system, all
the way to where the phone company wire enters the house.