I got the gpio demonstartion working last week, so I may be able to help
Once you have opened the gpio project, go to the "Sources" folder, then the "platforms" forder and open file k60_tower.h
At the end of this file is a section titled /* * Serial Port Info */
If you are using the tower with the separate serial/USB/Ethernet ports then uncomment the line
#define SERIAL_CARD // use this option for serial port on TWR-SER
and comment out the line
//#define OSJTAG // use this option for serial port over the OS-JTAG circuit
Rebuild the project and debug.
Connect the serial port on the tower to a serial port on your PC, and use Hyperterminal - set the communications speed to 115200 baud.
Good luck!