How do we import keys from the swing wallet to the GUI wallet?
I have no idea. We always discouraged users from using swing wallet...
In the future, the "backup" section of VoteCoin GUI wallet should contain sectoin to import private keys, so as long as you are able to export private keys from swing wallet, it should be possible to import.
The swing wallet is merely a cli front end to your windows cli wallet, so the instructions are as per your official windows cli wallet