Unhappy [Q] [TROUBLE]Help needed to bring back GNex trapped in the *long* boot(Soft brick?)

My GNex is struck in the boot loop and the volume keys are broken due to mishandling Due to that I cant go to the Bootloader/recovery

On browsing through XDA, I got a USB JIG and able to go to the Download mode. But from there I cant proceed.

I don't want to wipe the Phone data and others. Please guide me

Will flashing the kernel alone save the Phone?

Will Heimdall works with GNex?

Any ODIN Flashable kernels available for GNex?

Details:

ROM: CM 11.0 Nightly(KK4.4)
Kernel: Default CM Kernel (Before flashing the Franco's kernel)