Forcing speararmed units to use swords

As the title suggests, I would like to know how I might force units that use spears as standard (such as hoplites) to instead use swords as a primary weapon. I've tried changing the animation but this just causes them to fling around the spear as if it were some one-handed poor quality halberd.

Import the model, rename primary weapon to secondary weapon and vice versa, then export the model. That should work.

Import the model into what program/view what file?

Import to 3ds max with verci's CAS IE, just google it.