You cannot change the IP from the VM console because the root password is randomly generated and not knowable.
So, I think you have 2 options:
1. Temporarily shut down (or unplug from the network) your other server in order to get access to your VM. Then browse to https://ip.of.vm:5480/ and change the IP there.
2. Root the Alert Central VM by booting to single user mode and change the root password. Then reboot, and log in via the console. From there you can issue an "ifconfig" command to change the IP temporarily and then log in via the web admin and save the changes.