1.1.3 Update Guide
Firstly, you must be connected to a Wi-Fi connection and secondly if you have 'Customize' installed on your iPhone, you must uninstall them first as it currently does not work with 1.1.3. You will also need to reinstall any apps that are installed. Only update if you really want 1.1.3 as it is known to give errors and be buggy.
Before you start
Make sure your battery is charged, you don't want it to cut of half way during the upgrade.
You must have a Jailbroken 1.1.2 iPhone.
It is recommended to uninstall all apps before you proceed, then install them again afterwards.
You must have the latest version of BSD subsystem installed from the Installer.
You must have the latestest update of Installer.app
You must be connected via Wi-Fi.
Auto-lock must be set to NEVER (Settings > General > Autolock)
Step 1
All you need to do is locate the 'Official 1.1.3 Upgrader' by Conceited Software in the Installer.
It will install and add a app to the springboard.
Click the app.
Click YES to use hacktivation.
Click NO to restore, (unless you want to wipe a your music etc)
It will now download a package. This will take a while as it is around 180MB.
After it has downloaded, it will install. This will take about 20 minutes.
After it has installed, it will automatically restart the iPhone. When it turns back on, in may take longer than usual while it displays the apple, this is nothing to worry about.
That's it, you're done.