[64 bit] Cannot boot to Ubuntu 13.04 on laptop with preinstalled Win8 (UEFI)

Hello,

I have been trying to install Ubuntu 13.04 on a laptop that came with Windows 8 pre-installed (UEFI; I am a veteran Linux user, but completely new to UEFI).

I have been unable to get the laptop to boot Ubuntu (I have installed Ubuntu on a separate partition, using a newly created UEFI partition to boot from).

I tried to repair the boot using boot-repair (http://paste.ubuntu.com/5723354).

Boot-repair indicated that I should tell my BIOS to set the boot to the /sda8/EFI/ubuntu/shimx64.efi, but unfortunately I have no clue how to do this (I can get into the BIOS, but AFAICS I can only disable UEFI, not change a bootpath).

I would really appreciate any help!

Thanks,

Nico