Accessing my network from a remote location - hardware help

I want to be able to access, among other things on my network, my Synology NAS for audio streaming from remote locations.

I have an ADSL modem connected to SMC ABR7004 Barricade 4 port router which connects to the NAS thru a Gigabit switch via ethernet.

The problem I run into in setting up port forwarding is that the Barricade has a 192.168.x.x address while the modem's LAN address is 10.0.0.1.

I can't seem to change the Barricade's address range to the 10.x.x.x range and am not sure how to proceed or if this is even what I need to do.

The computers connected through the Barricade all get 192.168.x.x addresses.

Is it as simple as disabling DHCP server on the Barricade?

Here is a screenshot of the LAN setup page

http://tinypic.com/r/fz69aq/5