do exactly what you have done and then follow John's original instructions. Use the cursor left/right to go along the track until you hit an event. The voice will be written in the display when you hit the correct event. Erase it and replace with a NX voice from explorer or sound group by just choosing it (ping!). Don't erase the other events volume etc. The last voice that appears when you cursor will be the one that plays in the song.
exit and repeat for all tracks, including drums.
Save as technics sequence, but keep all your midi originals in an archive for future use.