Bulk change permissions

I have a CodiMD instance that was created allowing anonymous users to create and edit notes freely. Now that the event that we set this up for has completed, we'd like to make everything read-only. I've set CMD_ALLOW_ANONYMOUS=false, CMD_ALLOW_ANONYMOUS_EDITS=false, CMD_ALLOW_ANONYMOUS_VIEWS=true and CMD_DEFAULT_PERMISSION=locked. This works great for (attempts to create) new notes, but it does nothing for notes that are set to Freely.

I'd like (even as a database hack) a way to change the permissinons to Locked or Editable for all existing notes. I can't find anything in the documentation or elsewhere, it seems.