having trouble updating my iphone

What trouble?

More detailed info is required.

Which iOS version is your iPhone running?

Are you trying to update with iTunes on your computer, or direct with your iPhone.

What happens when trying and any error message provided?

The latest update for iphone and I was doing it via itunes on mac

tried updating iphone 4s via itunes on my mac. phone was updated with most recent version and was trying to install the latest update. it froze and now I need to restore or recovery and that got stuck twice.