OK
instructions are not present ((((under the link, only files
Isntall ubuntu 16 or something friendly with GUI on the virtual machine.
Download
https://github.com/iridiumdev/iridium-qt-wallet/releases/download/v1.0.0/Iridium-qtthen in the terminal
chmod +x Iridium-qt
./Iridium-qt
GUI wallet will be launched and synchronized.
Then you can send your wallet files created by windows to your ubuntu machine.
And then in the Qt wallet, File -> open wallet. It will show your balance.
Wallet just generates valid address and keys for it. So you can do all that stuff later. Or when windows qt will be ready.
Thanks for giving instructions, you should also install qt5 using this command before running GUI wallet, they may be required if it cannot open without them: