Hacking Hack PS VITA 3.55

[kidtrunk]

Hi everyone !

I wanna know if it's possible to Hack a 3.55 PSVITA linked to an EU account,
I know the vulnerable game is not present on EU store so i can't download it by using my PS3

So my question is What Should I do ?
Is it possible to change the PSVITA account linked (to a US account) without updating ? And then transfer it by using my PS3
( I don't want to buy this game for nothing )
Should I update my vita ? ( The vita ask me for 3.57 update )

Thank's for you help