So I burned tumbleweed (“openSUSE-Tumbleweed-DVD-x86_64-Snapshot20151022-Media.iso”) to a USB drive using my OSX machine and this guide. I powered on my computer and booted from the USB drive. Started installation and all went well until 96%. I got an error alert which described an “error installing boot loader” and gave me the option to try another configuration. I tried every reasonable configuration possible and every time it reproduced the same error.
I’m not sure what to try next, so I’ll be grateful for any help! 
Please note, the computer I’m installing on is a Toshiba Satellite pro l670-189.
Thanks for reading,
Sam.