I have done remote upgrades before, but its been a long time. So after I backup the system, then use the DM's file utility to upload the new files, and dump the old ones, and reboot what happens next? I plan to do this remotely, Will the IP address/password stay, so I can get back into the system and get to upload the database?

Does the embedded voicemail files/recording not get erased when you perform upgrade?

Do ver 4.6 cards need a separate firmware upgrade for 4.75?