Update from 10.10.5 to...

[OferSmi]

Here is the easy way :

Backup / Clone your existing installation then work with the clone leaving your original intact.

Start with the computer powered off.
Insert your USB installer.
Power on the computer and press your boot menu key - Usually F12 but YMMV.
At the boot menu screen select your USB flash drive as the boot device and boot.
At the Clover menu screen select your hard drive and boot
When you get to the desktop download and run EFI Mounter and mount the EFI partition of your USB.
Copy the entire /EFI folder from the EFI partition of your USB to the desktop.
Eject the USB.
Run EFI Mounter again and mount the EFI partition of your HDD.
Delete the entire /EFI folder from the EFI partition of your HDD.
Copy the /EFI folder from your desktop to the EFI partition of your HDD.
Rename the /Extra folder on your system partition to anything you like.
Restart

You should now be able to boot from your HDD in the same way that you could previously boot from your USB.

Ok I think I got this. I have the clone booting with clover. should I do the same to the none clone? or is there another step first?

 

[P1LGRIM]

Should I do the same to the none clone? or is there another step first?

Your choice.
The purpose of leaving your original intact is so that you may get back to where you started from if things go wrong.
I would take the clone to its ultimate conclusion first and then decide what to do with the original.

One thing to watch out for when you upgrade, be sure to remove the EvOreboot.kext if you have it.