ack up data on Desktop Manager under Back up/restore option. NOTE: If you get an error during this process, clear your browser cache (Browser > Menu Key > options > cache operation > clear all of them)
Back up your 3rd party apps. I use bbsak.
Disconnect your BB from Desktop Manager
Download desired OS to your PC In your case .419
Install/run OS to PC
, delete vendor.xml file. It�s located in c:\program files\common files\research in motion\apploader
Connect BB to Desktop Manager
Click Application Loader
Click Update
At this point, disconnect your computer from the internet. Optional. I don't but some people do
Select the OS you would like to load and continue
Do not unplug BB during the process. It will take around 20-90 minutes to complete upgrade.
Note: Make sure to back up your phone and third party apps prior to updating in case something.
Note: you can also load the o.s. by opening the app loader. Located in the same place you deleted the vendor file
Posted from my CrackBerry at wapforums.crackberry.com