Does anyone know how to export selected tracks from PowerTab as wav or similar?

I'm trying to extract Impellitteri's Somewhere Over The Rainbow from the .ptb off this site, but I usually use GP5 so I have no idea how to do it on PTB.

I figured out how to view the bass track but I dont really fancy manually transferring it to GuitarPro just so I can export a wav. The description also says it has a keyboard score but I have no idea how to even find that!

Any ideas?
Ibanez S470 (Condor/Pyro/Warthog)
Rockafeller Custom
Laney Lionheart L20H
Framus FR212CB
Morley Bad Horsie 2
Boss DS-1 (Monte Allum Mod)
Boss DD-6
Electro-Harmonix Small Clone
Dunlop/MXR Phase 90 (Full Script mod)
Voodoo Lab Pedal Power 2+