Download and Install the latest Deskotp manager from here.
Download and install the latest OS for your device from here.
Then follow the instructions from here.
Edit: ok, just noticed no OS is listed from Alltel for the 8830. What version OS do you have? Go to the sticky for the latest 8830 OS in the 8800 forum and use that one or there is a link in the first post of the sticky that takes you to each previous version. Just find a carrier that uses the same version number.
You can search the CDMA carriers for your version using the following link: BlackBerry Operating System Downloads - BlackBerryFAQ