In older models of hub and firmware, it used to be possible to change the DHCP scope (only the third octet though) which would change the hub's LAN address to 192.168.x.1 (the hub is always, always .1). I believe though that that feature may have been taken away from the newer hubs and firmware.
Your best bet would be to put the hub into modem/bridge mode which simply means that it 'passes' a WAN IP address to your own third party firewall/router. With your own kit, you are free to set whatever LAN addresses and subnets you want.