D80120G KDZ File
For D80120E: I lost root and recovery when I updated, but was able to re-root with towelroot. Here's a link to their website. Then I installed and ran AutoRec to install TWRP, then flashed Cloudyfa's kernel v1.3 to enable Knock Code.
D80120E KDZ File
http://oceanhost.eu/g92b383v7jqe/D80120E_00.kdz.htm mirror - thanks hyelton!
D80120A KDZ File
http://storagecow.eu/index.php?dir=X...T-Mobile+G2%2F mirror - thanks hyelton!
LG Mobile Support Tool...Thanks CollinFX45 for the link!
Latest drivers from LG (as of 7/2/14)
You can also download 4.4.2 through the PC Suite. Thanks elzero26 for pointing this out!
If you are having issues with updating your phone with the Support Tool or the PC Suite, you may have to update it following the directions from the link below.
Alternate method for updating software
As always, flash at your own risk.