use cool Editor
or GoldWave and loope them like 'cut' and 'Past' in new File
you have to 'select' from the first to the End of the Instru that you see it's better then copy it with
Ctrl-C
Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V Ctrl-V
sory for my english