[Q] LG G3(LS990) Root problem. topic

Okay. So I've decided that I wanted to root my SPRINT LG G3. The only legit method I've found was STUMP, which claims that my Phone is patched. Since I've never encountered this problem before, I have no knowledge of how I can upatch it. I've tried looking for other root methods but found nothing compatible with the LS990 LG G3. Do you guys know any other root methods, or a way to unpatch(Provided with links please.)?