I know you asked the question a couple of years ago and the question is top in Google so I thought it was worth putting our answer in.
We get asked this question a lot of times on SnapShooter.
You can’t download your DigitalOcean Snapshots and we don’t think this is ever going to be offered by Digita lOcean, but you can still restore your file as @Woet said.
The way we recommend our customers is to create a new Droplet from your Snapshot. Once it has booted up make sure you SSH in and disable and services you don’t want running (cron for example). You can now download the files you want using SFTP or if you’re more confident with SSH you could scp files from the temporary server to your original droplet.
Once your finished don’t forget to destroy your temporary droplet to save the cost of having it running. As long as you don’t destroy the snapshot you can keep doing this.
If you’re in the market for backing up your droplets more frequently checkout SnapShooter.
Founder of SnapShooter