Welcome to the Verizon forums. I beleive what you are referring to is downgrading your device's software to a previous version. To downgrade, follow the instructions below:
How to Downgrade Your Blackberry OS
1. Make sure you have Blackberry Desktop Manager (BDM) installed on your computer. You can download it for free at http://na.blackberry.com/eng/services/desktop/ for PC or Mac.
2. Download the OS you wish to downgrade to and install that file on your computer. It will integrate with BDM.
3. Backup your contacts, settings, and personal files on your Blackberry with BDM. This will save you from losing your contact list and other personal information.
4. To begin the downgrade process, start BDM with your Blackberry attached to your computer via the supplied cable.
5. Once BDM has started and you are at the main screen, click on Application Loader and then Update Software.
6. After the BDM reads information from your Blackberry, you will be presented with a list of available updates. Select the version you wish to install by checking the box next to the version and click Next.
7. After the BDM reads your device, the process will start. Once started, follow the prompts and do not unplug your device or the installation will become corrupted. The process will take 25-30 minutes to complete. When the installation is complete, you will receive a message from BDM stating so.
8. You may have to reinstall some programs such as Blackberry App World, special themes, or games you purchased. If you backed up your device, you can now allow BDM to restore your files.
9. To restore files and settings, go to the main screen on BDM and select Backup and Restore and then select Restore.
10. You will be prompted for the backup file from earlier, which by default has the date in the name of the file. Once completed you will be shown a message stating it is complete.
Hope this helps,