(adsbygoogle = window.adsbygoogle || []).push({}); Hello ngu...
i am new with all of this about Ps3 info but 4 start question is:

can Ps3Superslim 500gb to be downgraded on software way or I must buy Hardware device?

Superslim can't be downgraded nor jailbroken, but you should be able to use Cobra ODE with it, giving very limited development functionality to the PS3.