Can you define "get rid of"? And why put another box in the attic?
Are you completely eliminating the switch box entirely?
Either way, you need to find out what colors were used as the travelers of the 3-way. Start there and let us know what you have.
If as you say you have only a 14/2 and a 14/3 in the box it is most likely that you will splice white to white, black to black, and cap off the red. That way the other three way will act like a SP switch.