Tried searching for this, but found more on how to hack it rather than what I need to get done:

So I have the 3G Hotspot enabled and have no problems connecting devices to it and getting online, etc.

My only question is by default it assigns an IP of 192.168.1.x from its builtin dhcp server. I need it to assign an address from a different range, is there anyway to modify what range it uses?

Thanks in advance!