Installing whited00r is best to be made on a clean install and whiteout restoring backup.
Step 1: Backup your data
The installation process is safe and tested, but you are doing this at your own risk. For this reason we suggest that you backup your data (our firmwares have include an iCloud-like application to backup your Game saves to dropbox since Whited00r 5), and transfer your applications from the device back to iTunes on your computer by following these simple steps: Right click on your device name in iTunes, select “Backup” and then “Transfer Purchases”. You also could use other software like DiskAid to manually backup data, if you prefer
We absolutely recommend that you make a clean installation without restoring from the backup you created with the previous instructions, but just keep it just in case you really need it to recover some data. We will not provide support if this rule is not respected.
Step 2: Download the firmware
There are two different Whited00r firmware version for iPhone 2G: Normal and Unlocked.
Lots of iPhone 2G has been exported worldwide, so lots of iPhone 2G users are looking for a carrier unlock to use their device with any SIM card. You should choose Whited00r Normalversion only if you can legitimately activate you device via iTunes AND you don’t need carrier unlock (so you are using the original SIM card, for example form AT&T). All other users should choose Whited00r Unlocked firmware. If you are not sure use Unlocked firmwares.
Step 3: Install using iTunes
Install the iOS firmware using iTunes. Click on the restore key in iTunes while holding shift on windows or option on mac and then select the firmware you downloaded in step 2.
After restore, setup the device as a new device and you are ready to go!