Any firmware upgrade that Comcast deems necessary will be automatically pushed to the SBG6580 sometime after it goes on-line and is activated for your uncle's account. Unlike DSL modems and routers, cable modems and gateways generally do not have a local firmware update path; the ISP almost always controls what firmware is loaded on any given cable modem. There are a few exceptions, but they are very rare; and even then if the manually forced firmware is not the firmware that the ISP wants you to use, they will push their preferred firmware anyway.--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.