Are you trying to replace the switches with the module, or be able to control the light from EITHER the switch OR the module?
If you are trying to replace the switches, then you would just remove both switches, disconnect one traveler (cap it at both ends, use the other traveler as your "hot" lead, and wire it back up as if it were a simple inline module.
If you are trying to ADD X10 control, but keep both switches, I don't think you can use the setup you have. You would need to replace the switches with a 3-way X10 switch, or a pair of Smarthome switchlincs (or togglelincs).
The way I understand it from my own Smarthome switches, the smarthome switches work by using one of the travelers as a "hot" lead, and the other as a "signal" lead.
the switch at the "load" side controls the load, and the one at the "line" side is used to signal the other one to turn the load on and off (using the "signal" wire).