mobile

Hi, I have a real problem with my one-week old oneplus one that I hope I can get some help with. I've spent two days trying to fix the problem with my phone and its totally baffling me.
I managed to unlock the bootloader and root the phone and install twrp and SuperSU using the Guide : https://forums.oneplus.net/threads/g...nd-root.64487/

I experimented flashing roms. Then I tried Oxygen but hated it. So I wanted to revert back to the factory rom and then upgrade to 11S. Since then I haven't been able to unlock the bootloader. I am using fastboot because I am running a macbook pro with Bootcamp which has a small partition and limited filespace. In fastboot, when I try to boot from recovery, it returns with
FAILED (remote: Device not unlocked cannot boot)
Whenever I try to unlock the bootloader, the oneplus reboots back into twrp before I can 'fastboot reboot'.
I've found this link http://forum.xda-developers.com/onep...r-bit-t2820912 this afternoon, downloaded the folder, but now have no idea how to use the script or where to put it?? I hope that this would unlock the bootloader?
Can anyone help me please??
Apologies in advance for being a NOOB. I'm upgrading from an iPhone 4S so please take pity on me !