Full guide to install CyanogenMod 10.1.2 on LG Optimus G (part 2)

Almost a month and a half after the previous part, I believe it’s more than time to finish writing the second part. Before going further: 1) make sure you read part 1 first (it contains important stuff on how to fix a softbrick screw-up) and 2) the disclaimer again: this is a risky operation, proceed at your own risks and DO make a backup of the data you care about.

Step 4.1: root your phone

Android is based on Linux. Linux has this user privilege thing where standard user can’t do much stuff while root user can do about anything. Most or all manufacturers’ ROM lock the user out of root privileges, and the Optimus G is no exception, so the first step is to claim back those root rights. On the Optimus G, as with most Android smartphones, and as with iPhones (who said Android was more open? :s), it is done using various exploits. Quite a few tools are available, the one that worked for me (although I didn’t try them all) was Framaroot 1.5.3 (1.6.0 wasn’t released when I rooted my phone but I guess it works too), which you can download on this topic on XDA forums:
– download the Framaroot APK
– transfer it to your phone
– install it
– run it with the Gandalf exploit
– if all goes well, the phone will reboot and you’ll be root then. If not, you’re good to search the XDA board or other places for other rooting tools. You can also post in the Framaroot topic, people seem to be quite helpful there.

Optional Step 4.2-pre: get a GSF ID key

This step is optional but highly recommended if you plan not to install Google Apps: this is to allow you to download APKs from the Google Play store without having Google Apps on your device. Indeed, in it’s traditional openness and privacy-friendly ways, Google forces you to identify yourself from your phone via the Google Play app in order to be able to download an APK from the Google Play store. Actually, you’re not even supposed to be able to download the APK, only to directly install it.

However, someone made a Google Chrome (works in Iron too) extension, APK downloader that allows you to download an APK on your computer from the Play store. But in order to use it you still need to have a Google account and a Google Service Framework (GSF) ID Key. I suggest you go to the extension’s website (link above) to see how to install it and configure it (it explains how to get your GSF ID Key out of the Google Apps). For instance you could test it to download FreeGee (that’s the app we use in the next step).

Step 4.2: install a custom recovery

The default “recovery” mode only offers to wipe out the memory so as to obtain a factory reset. Not very helpful to install a new OS. So now that you’re root, you need to install a custom recovery. More specifically, ClockworkMod Recovery, because the alternative TWRP, which I tried first failed at installing CyanogenMod for me. I believe my ClockworkMod version is 6.0.3.0, but anyway the tool to install it will only offer one version. I believe it will offer the choice between a “touch” and a non touch version, they are similar except for the fact that the touch version, as it names says, support the touchscreen while the other can only be controlled using the volume and power buttons. I tried both, the one without touch is easy enough to handle and nice to avoid accidentally selecting an option, but in the end I still preferred the convenience of the touch version.

Anyway, in order to install ClockworkMod you’ll need to unlock the phone. The tool I used for this was FreeGee. It’s actually quite all automated, since it does all (unlock, download ClockwordMod and install it) in just a few guided clicks. However, it said I had unlock using the SBL method, which it says is risky (risky as in hard brick, no soft brick). Maybe make sure Shelnutt2 is on freenode irc #lg-optimus-g before proceeding if you’re scared and want to make sure some help is available. However, when I did my unlocking, I asked and was told that at the moment there had been no report of a hard brick on Optimus G. Again, the decision is yours to make.

Step 4.3: install CyanogenMod

Here is the final step, which is actually one of the easiest, and should in my opinion be the only. This is now as simple as installing a new OS on a PC, except if you also want to install Google Apps, in which case you’ll need to grab the proper zip package from http://goo.im/gapps, and flash it the same way as you flash CyanogenMod (not tested – my main motivation for installing CyanogenMod was to get rid of Google stuff).
– download any version of Cyanogenmod for the e975 (I think it’s better to just get the latest stable one in the first place, so if it screws up you know it’s not because of a broken nightly)
– place it in the sdcard folder (there’s no sdcard in the Optimus G, but there’s a folder named like this)
– boot on the recovery: we saw in part 1 how to do this, that might actually be the hardest thing to do in this step, since the key combinations can be hard to get right: maybe it’s easier to reboot via terminal by typing reboot recovery as root (su then reboot recovery)
– once you’ve rebooted into ClockworkMod, browse around to install CyanogenMod and also wipe the cache. If CyanogenMod crashes at startup, you might have to go back to recovery and also wipe the data.

Well, that’s “all”! You should now how have a great new ROM 🙂 Just a little tip for the road: in Android >=4.2, the developer mode is hidden by default. To allow it back into the settings menu, go to Settings => About phone and then tap multiple times on the Build number.