how i get software update for iphone 3g from 4.1 to 5.1

Yes, that is what my phone version is on but the apple store assinant said that I have to make sure i sync everything so then when it upgrades I will have to start fresh.

Huh?

You asked "How do I update my iphone 3g from the version 4.1 to 5.1 from my phone?"

The answer is you CANNOT update to 5.1.

Not sure I understand your last comment.

I'm not sure what they told you but you can't update it any further; not if it's a 3G.  If you have a 3GS you can update it to the latest iOS (5.1.1), but not the 3G.  If you aren't sure which model you have check your phone against this: http://support.apple.com/kb/HT3939.

okay but I was just making an understanding that you can said some lady and something about holding down the off phone while it is restoring??

No idea what you are talking about.

"Some lady"?

What are you trying to do?

Please start over, as your posts are increasingly confusing.