If you just want to use very simple ASCII text notes - i.e. without the web clipping and other features of Evernote - you can convert to SimpleNote using this process:
- export from Evernote using the HTML (multiple pages) function to a new directory on your drive
- download and use htmlastext (http://www.nirsoft.net/utils/htmlastext.html) to convert the HTML files to text files
- download and use ResophNotes ( http://www.resoph.com/ResophNotes/Welcome.html ) to import the text notes, and then sync with SimpleNotes
Be aware that all you'll get is just simple ASCII text - no