You're right chuckkahn, the backup solution is not very good. But as DTlow mentioned, it really is just a precaution in case something goes horribly wrong. It isn't necessary for the move to the alternative version of Evernote.
To create the backup,
select all your notes using Cmd+A, you should see the count of selected notes displayed just above the buttons for merge, share, create table of contents, etc.
On the menu choose File>Export Notes...
enter the file name and location for the backup.
After it starts you should see the count of saved notes progressing.
Once the backup is finished you could copy or move it to an external disk if you were feeling really cautious.
DTLow is right with the advice not to over think it. I deleted the old app before installing the new one but it doesn't seem to matter. After installing the new app it automagically copies the the database to the new location.
After a few weeks I deleted the old database and haven't had a problem since including with updates to my current version "7.5.2 (457164 Direct)"
Hope that helps a bit.