change inside ip on pix 501

Hello I am trying to change the inside fixed ip address of my cisco pix 501 using pdm. When I try to change it from 192.168.1.1 to 192.168.0.1 it errors out because the dhcp pool is in the 192.168.1 subnet. So I disabled the dhcp but it still will not let me change it. If I try to change the dhcp pool range then it will not let me do that because the router is still in the 192.168.1 subnet. What am I doing wrong and how can I change the routers IP and the dhcp range? Thanks in advance!