Before uninstalling, please verify your data is synced by checking the Server Dashboard. See here: How do I know if my data is synced?
- Save a copy of the encryption key from Day One > Preferences > Journals > Show Encryption Key
- Quit Day One Mac.
- Paste this into the Go to Folder window in Finder: ~/Library/Group Containers/5U8NS4GX82.dayoneapp2/. (See screen shots below.)
- Drag the entire folder to your Mac Desktop. (This contains a local copy of your journal data backups and might be useful if any problems arise when you reinstall and reimport your data into Day One Mac 2.0.)
- Drag the Day One Mac 2.0 app from the Applications folder to the Trash Can.
- Be sure to quit Day One Helper in the menu bar if necessary.
- Go to the Mac App Store > Purchased and click Install for Day One.
- Sign in to Day One Sync. Your data will download again.