Wirelessly posted (8310; The Juggernaut)
I don't believe TMo offers any data plan with a prepaid accout.
The only updates you can do are OS upgrades. Look at the TMo website for your model, and download the OS from there, or find specific directions to upgrade in the faq section here.
http://www.blackberryfaq.com/index.php/Main_Page.
And, welcome to the bbf.