Need help jailbreaking 3gs old bootrom 4.0

[j3ff12ey28]

I have no idea how to go @ this. I tried searching & couldnt really find a guide or answer. I have an Iphone 3GS old bootrom never been jailbroken before on 4.0 firmware 05.13.04 baseband. How do I jailbreak this thing? Can someone please help a noob out. TIA

[iYeow]

Go to safari on your iphone , jailbreakme 2.0 and slide to jailbreak your 4.0