Problems Rooting SPH-L520 with Kies/Kingo

[foncall]

I posted this question over on xda-developers.com a week ago and haven't received a response, so I thought I'd see what I could turn up here:
I would like to root my SPH-L520 so I can flash it to Boost Mobile as a replacement for my long-in-the-tooth TP2. To do this, I followed a guide I found on andromods.com (http://www.andromods.com/root-unlock/sprint-galaxy-s4-mini-reroot-sph-l520-latest-ota-update.html). My first step was to establish a USB connection between my SPH-L520 and my PC (Windows 7). You use Kies for that, right? Well, Kies would recognize that there was a SPH-L520 connected, but it wouldn't actually connect to it. It just kept saying “connecting” for half an hour. So I shot-off a support request to Samsung asking for the appropriate drivers for my phone (none are listed on the webpage for the device) and Samsung said there aren't any drivers for the SPH-L520. Kies does connect my SPH-L520 and my PC via WiFi, though, so I thought I’d try to go ahead and run the Kingo rooting program. So I enabled Developer Mode (by tapping on “Build Number” several times) and enabled USB Debugging and ran Kingo. Kingo connected but saw my Samsung device as being in “Normal Mode” (I’m guessing it should have said “Developer Mode”?). I went ahead and clicked on the "ROOT" button and my phone failed to root. I tried it several times and it failed every time. Phone stats are below. Any suggestions would be greatly appreciated.
Model number: SPH-L520
Android version: 4.2.2
Baseband version: L520VPUAMK2
Kernel version: 3.4.0-2054908
Build number: JDQ39.L520VPUAMK2