Q: back to old Notes

Hi,

i accidentally upgraded Notes to the new el Capitan format. This now allows some fancy new features within the new Notes, but it also locks out my old iPhone 4 sync because it's running on iOS 7.

(I didn't saw any upgrade button or warning box which explained this drawback during upgrade to el Capitan, but maybe I simply missed it)

So I want to have the sync between my el Capitan Mac and iPhone 4 back, even if loosing the changes done in the last days on the new format. I've already tested with another old Mac still running on Yosemite and temporary switched to my AppleID that the sync to my old iPhone working in general.

How can I install the old Notes app working with the old format on my Mac on el Capitan?

(Copy of the old Notes.App from Yosemite over to el Capitain ended with a crash - it's not so simple :-(

Thanks

   Achim