You can downgrade from one version to a previous version, but not always can you go backwards one release. Fedora24 libraries may not be compatible with with those of Fedora 23. Your best bet is to install the Fedora 24 Alpha7
https://dl.fedoraproject.org/pub/alt/... and take the alpha7 version. It is very clean.
I would save your /home partition, and with anaconda, you may reinstall, reformatting /, /boot, swap, but definitely not /home unless your wanting to start cleanly.
On or about May 3, the first Beta will be released. So far, for my workspace needs, I have not encountered problems.
If you really want to return to Fedora 23, I highly recommend Chapeau Linux ( www.chapeaulinux,org , which is Fedora 23 + audio/visual/ and some extras.
Well, the easiest way is to download a F23 media and re-install the OS. If you can wait until June, you can get the 24 stable media.
Also, check FAQ's here...