HOW TO: Update Your iPhone to iOS 5.0.1 Over The Air [tutorial]: 
Turn on and pick up your iPhone
Connect to WiFi
Open the Settings app
General
Software Update
Download & Install
Wait a few minutes for the software to install
Your iPhone will automatically restart
Maybe more than once (one of ours restarted twice)
That’s it!
Let hope those battery life issues are finally behind us, because iOS 5.0 really sucked.
HOW TO: Update Your iPhone to iOS 5.0.1 Over The Air [tutorial]:
  1. Turn on and pick up your iPhone
  2. Connect to WiFi
  3. Open the Settings app
  4. General
  5. Software Update
  6. Download & Install
  7. Wait a few minutes for the software to install
  8. Your iPhone will automatically restart
  9. Maybe more than once (one of ours restarted twice)
  10. That’s it!

Let hope those battery life issues are finally behind us, because iOS 5.0 really sucked.