Thanks to this great forum threat: “The Big N00B how-to!” I’ve managed to get CyanogenMod 10.0.0 (Android 4.1.2) installed on my LG P970. I spent literally hours just trying to get ClockworkMod installed… ROM Manager seemed to get stuck at 100% of the installation, and nothing else I tried work.
After many attempts and different combinations, what worked for me was downloading the CyanogenMod zip and putting it on my phone’s SD card (while you’re at it, you should probably download the Google Play Store app from http://goo.im/gapps or http://androidjinn.com/download-latest-gapps-or-google-apps.html and put it on your SD card as well), and download the V20 rom from the forum thread above, and flash with SmartFlashTool (see my previous thread about using it).
Your phone should restart in to ClockworkMod Recovery, the touch-screen buttons (at the bottom of the screen) work as follows: “Menu” scrolls up, “Home” scrolls down, “Back” goes back a menu option, “Search” selects/runs the highlighted menu option. Find the options that will clear all the cache and data (assuming you’ve made backups), then the use the option to install zip files to install the CyanogenMod and Google Play Store zips – probably wouldn’t hurt to to “Fix permissions” under the “Advanced” menu options, and clear caches again. Select the “Reboot” option and you should be good to go.
Installing Play Store after CyanogenMod:
If, like me, you didn’t install the Google Play Store at the time of flashing CyanogenMod on to your device, you can easily get back in to ClockworkMod by holding the power button (while the phone’s on) and selecting “Reboot”, then “Recovery” and using the instructions above. Once again, probably wouldn’t hurt to “Fix permissions”.
Recovering from “Security Error”:
While trying to get ClockworkMod installed on my P970, I got it stuck in a “Security Error” loop whereby turning it on would display that error in text then shut off. The problem with this is the OS doesn’t boot for you to be able to re-flash software on to it. With your phone off and unplugged, hold down the “Volume Up” button on the side of the phone, then plug in the USB cable… the phone should switch itself on and display a “Software Update in progress” screen. Use SmartFlashTool (once again, see my previous thread) and you should be able to write flash working software to it.