I acquired an LG G2 (LG-D802T 32 GB) that is running the most recent stock firmware. I'm trying to install Cyanogenmod on it. However, I cannot root it. The most recent firmware is patched against various rooting tools, including ioroot and Stump Root. I cannot find an alternative way to root this phone.

Are there other ways of rooting the LG G2? Is it necessary to root the phone in order to install Cyanogenmod, or are there other alternatives (e.g. "download mode")?

(I think I can first revert to an earlier firmware version that is unpatched, but cannot find an image for my model.)

EDIT

I've attempted rooting with the "New Root Method for LG Devices", adapted for Linux. This did not work. I also tried the more recent "Newest Root Method for LG devices", adapted for Linux, which also did not work.

I'm wondering what the dangers are for flashing the wrong firmware for my model. I know that there is an image for the Australian LG-D802T, but I don't know if this is for the 16 GB or the 32 GB. After downgrading to this image, this may hopefully re-expose the vulnerability required for rooting. If I accidentally flash the (incorrect) 16 GB version, but immediately install a custom ROM anyway, would that be a problem?