How to upgrade my iPhone 4 with iOS 6?

How do I upgrade my iPhone 4 with iOS 6?

Go in to settings then general, software update, it will tell you that there's new sift ware and follow instructions.

Settings> General> software update
(You must have 2.4 free gigs of memory to get it, but after the update is installed you no longer need that memory free.

It screwed my phone up when I got it. It's having trouble send/recieving messages. I don't recommend getting it.