In my opion you have two options:
1> Reuse your old wires (cut solder/heat shrink) Works great, I just did mine.
2> Wait to change them the next time you have your drive off.
Replacing the switches can be done with a 12 inch 1/4 inch drive extension and a 7/16 swivel socket.Put the drive all the way down and you will be able to see the bolt that holds the wires into the transom plate.
And it can be done without removing the drive...