This is the second edit. Thanks to zanakorus33 for providing the tip for modification of the file. Since .bat is not allowed to attach, I put it up as text file.
The following method is applied to both international version (P760) and T-Mobile US ...
Note: This method works with both 10i and 10j
I have read few posts arguing can root be done with 10i. I have been hesitant until last night. After I fixed USB 3.1 problem by updating the driver, I decided to give a try.
I updated mine with LG...
Update: I used Linux machine instead of Windows and the latest kernel works now.
1. Your L1
2. Installed drivers (Sony so0112 for both ADB and fastboot)
Credits go to: ashyx, mauam, jedld, Chainfire
Padded kernel for T280
http://forum.xda-developers.com/attachment.php?attachmentid=3881481&d=1474417563 (unpack with 7zip and put it to memory card)
SYSTEMMODE SuperSU (REQUIRED)
Update to 7.0 and dirty cow root can be found there.
Latest dll for LGUP