Jailbreaking the 3GS from 3.1.3 to a newer version?

hi all, have jailbroken , unlocked iphone 3gs (i didn't jailbreak it). wanted install viber push notification error figure need new version of ios. not familiar whole process can explain me how can updated working version? told risky go straight 3.1.3 5.0 because bricked. installed itunes , used redsn0w , ipsw file jailbreak , open 3gs , still see version still @ 3.1.3 nothing worked me.
can give me advice on how upgrade without issues?

 

Forums iPhone, iPad, and iPod Touch Jailbreaks and iOS Hacks

• iPhone
• Mac OS & System Software
• iPad
• Apple Watch
• Notebooks
• iTunes
• Apple ID
• iCloud
• Desktop Computers
• Apple Music
• Professional Applications
• iPod
• iWork
• Apple TV
• iLife
• Wireless