On my Klein, the cable stops in the top tube (rear brake) are at both ends, but the cable stops for the derailleur cables in the down tube are only at the top (makes sense).

The proper way to do this of couse is to put cable liner through the tubes before you remove the old cable.

I've been successful using a thin piece of copper wire to find the downstream hole but I had to take the cable stop insert out of the back end of the top tube first.

I envy all you guys with air compressors though.