I purchased business class for a whole lot of reasons but one of the most important is to get a rotating IP address. I've tried the button in the back of the modem and ipconfig command on the command line and neither seemed to work. Does anyone have any idea how to force my IP address to rotate?
I'm not sure what you mean by "rotating"?
If you mean a dynamically changing address, there's no need to get business class for that; resdiential service and business class w/a bridged or customer-owned modem receive addresses via DHCP/DHCPv6. The only way to get a new address is to either manually change your MAC address of your connected device, or wait for the DHCP lease to expire and take your device offline shortly beforehand.
Note that Comcast closed the "rotating IP address" loophole a couple years ago when they realized that spammers where using that to basically walze through vast swaths of IP addressing to send spams.
The usual trick was, a script would bounce the interface, when the interface got a new IP number the script would modify a DNS server entry (with a real short TTL) then they would commence spamming, then when the RBLs started blacklisting they would stop spamming, bounce the interface, get a new IP address, update DNS, start spamming, and so on and so on and so on.