transferring 8900 to new phone service provider

Hi,

If I purchase an Audiovox 8900 that's
been activated on Verizon, Telus, or
any other provider using CDMA, how
do I go about unlocking and/or reprogramming or whatever to put
it on Cricket Service (also CDMA.)

What does it mean if an 8900 already
comes 'unlocked' as far as moving it
onto Cricket service?

Maybe the answer to this is obvious to
all of you, so I freely admit I'm a newbie
at this stuff. I'll be thrilled if you can point
me at a website or FAQ that answers
the question.

Thanks in advance.
gfr437