I found the ground wire splice about 12" down from the #1 injector plug. For the connections I just cut out the corroded pieces and soldered the wires together. I didn't have to cut out much wire so I didn't see a need to add any new wire. If you do cut out a lot of the old stuff, just make sure the new wire is the same gauge.

1987 4-Runner with a "slightly modified" 22RE