Exporting 5.1 audio as 6 individual mono audio tracks

I am working on feature length documentary with Premiere Pro CS6. I have assigned a 5.1 audio format for my project.

The problem: when I try to export the 5.1 audio mix as a WAV file containing all 5.1 channels with a resolution of 24 bit, the encoder comes back with an error message. The problem obviousely is the size of the WAV file which cannot be bigger than 4 GB.

The workaround: when I am reducing the resolution to 16 bit (instead of 24) it works out fine. In that case the file size is less than 4 GB.

Since I am reducing the resolution down to 16 bit I guess that I am also reducing on audio quality. So my idea was to export each of the 5.1 audio channels one by one as separate WAV files to overcome the size limit of the WAV files. BUT: how can I do that? Is there a way to export each of the 5.1 tracks individually?

Any ideas?