today I got myself an LG G Pad 8.3 because I liked the hardware. Unfortunately, LG's software ist almost as bloated and ugly Samsung's . After a lot of searching through this forum and elsewhere i finally managed to get this tablet from KOT49I.V50020D (KK 4.4.2) to CM11. As all the other guides are for older versions/builds of the OS and never cover the whole process I'm trying to do a little tutorial here. It was a little harder than rooting my Nexus5, so I don't really recommend this for newbies.
Credits to the respective creators of the software, hacks and methods used in this Tutorial. I didn't do any coding or magic.
As always: No guarantee this will work for you!
I am not responsible for what you do with your tablet, phone or life.
The first thing I did was to root the G pad using IOroot (Credits to autoprime).
1.1. Enable Dev.-Options by clicking the build-number 7 times.
1.2. (while your G Pad is not connected to a PC) enable USB Debugging
1.3. Connect to your PC, You will need the LG Drivers
1.4 Unpack the Zip-File from the thread and open a commandline in the folder
1.5 Check communications using "adb devices"
1.6 "adb reboot recovery" to boot into recovery mode (obviously)
1.7 move to "apply update from adb" using the volume-rocker, select with the power button
1.8 (On your PC again) "adb sideload kk_root.zip"
1.9 The installer will do its thing, you should see "DAT ROOT" when finished
1.10 reboot your system (see 7.)
In the next step, you will install a custom recovery.
Or lets say, you will let a script install a custom recovery for you. (Credits to Drgravy, id10terror and samuraix21)
2.1. download the zip-file from id10terror's thread (his Step3). The download may be slow
2.2. unpack and right-click the *.bat-file -> Edit using an editor of your choice
2.3 change the letter at the end of the build-number according to samuraix21 (second post in his thread), then save
2.4 run the batch-file, the tablet will reboot after this step
2.5 put the newest version of TWRP on you G Pad's internal storage
2.6 repeat 1.5 and 1.6 to get into your new recovery
2.7 immediatly after the screen goes black, pull out the cable (for unknown reasons)
2.8 install -> select the recovery you just moved to the internal storage, swipe to confirm
2.9 wait until finished, go "home", reboot system
That was the hard part. Flashing CM or any customRom is fairly easy
3.1 Download the latest CM-Snapshot from here
3.2 Place that zip-file in the internal storage as you did with the TWRP-file. You can erase that one.
3.3 repeat 2.6 and 2.7
3.4 Wipe -> Swipe to confirm
3.5 Install the CustomROM as you did in 2.8. This might take a little longer.
3.6 see 2.9
3.7 The display might be very dark while booting. You can change later
If everything went right, your tablet now runs a rooted customROM =)
Sorry for this wall of text