How to solo mine & Success chance?

Hey guys, so I've been mining RVN for a while and have earned a bunch already, however I've got a build of 2x gtx 1080's and they barely earn much, so I was thinking of setting them to solo mine, atleast if I were to successfully find a block, that's a good 5000RVN eh?

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Can anyone guide me on how to solo mine aswell as what my chances roughly are? Thanks a bunch guys.