Download these files (if you have D958):
Make sure to add your account name in terminal command. Eg: "dd if=/home/your name/Desktop/sbl1.img of=/dev/sdb2
You can use a virtual machine.
Before doing any of the above steps enter download mode using these:
-Turn off you phone by pressing for 15 sec on power button.
-Then, while holding volume up button connect your usb cable.
-You should see your phone in device manager as qhsusb_bulk. Install qhsusb_dload drivers in device manager using browse and locating the 32bit driver file.
Then you just follow the guide and it's fairly easy.