Chrome Browser for all the iOS devices is already out now and at the top of the app store. But using a 3rd party browser is not very helpful when you are using iOS. You cannot actually change that as it is set by Apple. But that ends today. If you have jailbroken your device already, there is an app for that ;)
You will have to download the free Cydia plugin BrowserChooser in your idevice and then choose your default browser as Chrome. Thats easy and simple. Nothing else to make it complicated. This tweak supports not only Chrome but also other popular third party browsers in the app store. So if you have other browsers in mind, you can try your luck.
Source
