Hmm, the link works for me.
Anyway, the procedure is simple
Just turn it all off, disconnect the USB lead from the modem, connect the ethernet lead from the modem to the PS3, then turn on the modem & let it boot, then turn on the PS3.
Also, Telewest used to at one point require that you register the MAC address of every device you want to connect to the modem (via a page on the TW website I think)... I'm not sure if it's still the same now with ex-Telewest parts of Virgin, but I don't think so.