How do I uninstall Yosemite?

[Derek]

I downloaded the above and it will not work with Nikon's NX2 which I really like to work with. Nikon will not be up grading NX2 to be compatible with Yosemite so I need to go back to Mavericks.
Will someone please tell me how to do it. Thanks

 

[honestone]

If you made a bootable backup before you installed Yosemite, you could boot from that backup, use Disk Utility there to erase your internal drive, format/partition it, and do a restore from your backup.

If you don't have a backup (baffles me why folks don't do this! It is actually quite simple, and a definite safeguard), here are the results of a google search I just did for "How to uninstall Yosemite":

https://www.google.com/search?q=How...la:en-US:official&client=firefox-a&channel=sb

Maybe someone can point you to a specific way. When you are done with it, you need to start making frequent backups.