Guys, I'm coverting the old direct drive starter on my daughter's '61 Plymouth's 225 /6 to a modern style gear reduction unit.

Her old starter has one wire coming from the battery side of the fender-well solenoid. How do I need to run my wires for the modern two wire starter? Thanks!!!

There must be a relay similar to the common ford relay that you will need to grab the small trigger wire from and extend to the new starter instead of the relay.
Just follow the fat starter cable and it should end at the relaly you need to steal the small wire from.

easiest would be to run a wire from your ign switch "start" down to the solenoid terminal on the new starter or if the ign sw has no place for that then a seperate pushbutton sw or better yet since the brown wire looks like it handles a fair amt of current would be to convert to a modern 4 terminal starter relay

No the easy way would be to use the heavy gauge wire going from the relay to the starter as the battery supply on the new starter by moving the relay end from it's current post over to the battery cable post on the relay and making up a new 10ga wire to go from that post of the relay down to the small post on the new starter..

Easiest way is to leave the original wiring and solenoid, then add a jumper as described above.

Guys, I wanted to say "thanks" for everyone's time. The jumper trick worked great! However, you can't swap out a direct drive starter for a gear reduction. The gear on the direct drive sits further out than on a gear reduction. The gear on the gear reduction doesn't kick out far enough to engage the flywheel. I'm going to have to get her old DD starter rebuilt - thanks though!