How to flash this:
1. Reboot into bootloader
2. Flash TWRP if you don't already have it. Current version is 220.127.116.11 fastboot flash recovery xxxxxxxxxxxxx.img (where xxxxx is the filename)
3. Reboot System
4. Copy the entire contents of the zip file to your TWRP/BACKUPS/LG0000XXXXXXXX folder. Make sure you copy the folder 2014-11-30--23-35-25 LRX21P.L004 or 2014-06-26--18-41-18 KTU84P.L002. If you don't have a backups folder, create one in TWRP by choosing Backup, then backup something like the boot partition.
5. Reboot to Recovery Vol Dwn+Pwr or adb reboot recovery.
6. Choose Restore and select 2014-11-30--23-35-25 LRX21P.L004 or 2014-06-26--18-41-18 KTU84P.L002
7. Once finished Reboot System.
8. Upon boot you should be greeted with the usual Setup screens.
9. Reboot into bootloader
10. (Optional for Kit Kat) Flash stock recovery: fastboot flash recovery 17-recovery.img
11. Reboot into system
Flashing the stock recovery is optional however if you want a completely stock experience and ensure future OTAs, you probably want to do so. Also note that you must unroot to take any future OTAs.
L Backup contains cache and stock recovery partition, if you want to keep TWRP or root, you will have to flash or boot into TWRP.
TWRP BACKUP 5.0 LRX21P.L004
TWRP BACKUP 4.4.4 KTU84P.L002
KK Stock Recovery