I also just got a Shuriken SR270, but luckily it came with the VDI USB interface, VDI Cable, etc.
Once you get a VDI cable, the manuals above were helpful but a bit out-dated for what software to use, at least from my recent experience. I was able to update the firmware and reset the patches (wanted a clean slate) using "Line 6 Updater". I was connected with the VDI USB interface. Best I can tell, the "Line 6 Monkey" software is not to be used anymore to update the firmware.
To use "Workbench HD" which is how you configure the models and tunings, I had to connect my Variax to my Helix pedal and then the Helix pedal to the computer via USB in order for it to recognize the guitar. You should be able to use the VDI USB interface, but I didn't have any luck with that.
