Fastboot flash aboot, boot and laf partitions from
HERE. Also fastboot flash
twrp recovery img. That should restore download mode with the bailout plan of a working custom recovery if you have any problems. When done, unplug phone and long press power for no less than 15 seconds to power off. Once off, press and hold volume up while while plugging into pc to get download mode.
Once in download mode, use the instructs in the 2nd half of the OP
HERE while using the 26a tot and lg flash dll from
HERE as your source files. Last zip in that link is the 26a tot, unzip it to reveal the tot. The lg flash dll for the vs980 is the 4th file from the bottom.
If you don't already have fastboot set up on your machine, use our forum's mini sdk explained and linked at the bottom of
THIS post.
If you have issues getting fastboot connectivity, download
PDAnet to your machine. Don't even have to run it as it comes packaged with a standalone driver package which should auto apply when you connect your phone in fastboot mode. If necessary, reboot after PDAnet is on your machine while the phone is still plugged in and in fastboot mode and it should pick up the drivers upon reboot.