Configuring cisco 7902g

Hi,
what I need to know and what I have to do to configure a cisco IP-Phone 7902g?
I haven’t Cisco Call Manager running (and I don’t know what CCM really is),
someone used the phone before me, have I to reset it?
The “cisco config” section in asterisk@home will help me?
Thanks in advance,
C.

Wich is the eaisiest way to upgrede the firmware of this phone in order to make it works with sip?

C.

The SIP software images must be purchased from Cisco or a reseller. They are sold either on a per model basis or in different levels through SmartNet. You may want to look here for some reference. Please note that I am not sure whether the 7902 has SIP support or not. To my knowledge, only the 7905, 7912, 7940, and 7960 have SIP support.

While the Cisco phones are very powerful, they may be overkill for a home install. You might want to consider some other (cheaper) phones which support SIP nativly and don’t require you to mess around with loading different software versions.[/url]

First of all thank you for your answer,
at the moment I’m trying to use it with sccp,
but I’d like to know (an maybe my question has no sense) what happens if I try to put in my 7902 phone the firmware of one 79xx phone supporting SIP,
Thanks again,
C.