How do I boot to Windows 8 from Ubuntu 13.04 on a dual-boot EFI install? (No Grub)

How do I boot to Windows 8 from Ubuntu 13.04 on a dual-boot EFI install?
(No Grub)

So I just got a brand new Dell XPS 13 which comes preinstalled with
Windows 8 Pro. I decided to install Ubuntu 13.04 and dual-boot. I made a
bootable USB, booted up the Ubuntu installer and found that it didn't
recognise my Windows 8 OS to install "alongside", so I realised I would
need to make my partitions manually. I went back into windows and used the
disk manager to shrink my C drive by 100GB. There were about 5 other
partitions like EFI and stuff that I ignored. Then, back to the ubuntu
installer, made a primary partition of ext4 and a 20Gb Swap partition. I
finished the installer, and Ubuntu works great!
Now my problem. I have no way of booting Windows. Every time I start the
machine, it goes straight into Ubuntu. I have tried holding down Shift,
but don''t see any GRUB screen. Ubuntu works great, but how do I boot to
Windows???