Fixing Installer Errors

Hi folks,
today, as lots of people I was in a internet cafe trying to update my iPhone, from 1.1.1 to 1.1.3. Before starting the procedure I decided to update some of my softwares, for example OpenSSH, Installer and so for. During the last upgraded (Installer.app) my iphone ran outside the disk space and the installation process was broken. The result ? Installer.app application didn't start. It was orrible, you know, without Installer.app you can not install 3rd p. application included the 1.1.3 soft upgrade.

So, let me write this post describing how to prepare you iPhone to the "big" upgrade.
First of all Backup your iPhone ! If something goes wrong you gotta restore your device, that means lose all your personal information like: Contacts, Configurations, Messages, Mails and so on.... I really don't know if there's an application which does that; but it's so easy using the shell in order to move some files that, to me, it makes no sense installing another application.
You need to backup these folders:

Then, you need more free space. If your device is running out of disk space means that the Installer partition (not Media) is full. In others words, if you've seen something like that:

You need to modify some files location.You can follow two ways:
The first one is the easiest, log-into your device via SSH and move your Application Folder using the following commands:

With these commands you move the Application folder and you create a link to the new location.
The second solution needs to install another software on your iPhone (available in Installer.app) named "Fix Disk Space"

Ok, now you got a backup and you have just fixed the disk space problem. Now shell we try to fix Installer application. Installer.app usually stores the temp files in /var/root/Library/Installer/Temp. If the installation has been wrong, you'll find here the zip file because the Installer.app deletes the sources only at the end of the installations process. Here it is !

Well, now you can overwrite your Installer.app file located in /var/root/ROOT_Applications with the decompressed file found in the Temp folder. Now you got enough space to do that and you're iPhone has been fixed. You are ready to upgrade you firware.