On the left you have your motherboard's boot menu. You can see Windows and Mac OS X added their entries when they were installed. As mentioned previously, the Mac OS X is useless to us.
In the central toolbar from top:
- Move selected entry up the boot order
- Create new entry
- Remove selected entry
- Edit selected entry
- Enable/disable entry
- ...
- ...
- Move entry down
All you do is select the EFI partition in the Disk/Partitions display, then add a new entry.
In the window that opens: Fill out the form, name the entry 'Clover', change type from 'Windows' to 'Other' and browse to efi/clover/cloverx64.efi to set the path.
Note that the UEFI boot menu is a list of paths, not disks as used in BIOS booting.
Just leave the windows entry alone. Windows "needs" it to boot - even if you start it from Clover.