Recover old mist wallet on Mac

I have some ether stored in an older Mist wallet. Of course that wallet no longer syncs. This was on MacOS X.

I see there is an /Library/Application Support/Ethereum Wallet folder which is still present.

How do I use its contents to recover these ether?

I would prefer to do so locally without exposing the keys on the internet. So these online wallets worry me.