Install openSUSE to removable SSD stick

I have no DVD drive on my netbook. I have openSUSE 13.1 installed on my tiny 16GB SSD (on the motherboard) main drive. I did this by using a live KDE USB stick. I now want to install 12.3 on a removable SSD stick. But using the same method results in an un-bootable SSD because the installation assumes it's going on a normal hard drive instead of a USB device and the BIOS will not boot from it afterwards. How do I work around my problem?

Thanks in advance.