Linksys Wireless Router :: WRT54G - How To Access Setup Page

When I had DSL, my WRT54G was my DHCP master for my home network.  When I got AT&T U-Verse, their "gateway" became the DHCP master and also the wireless access point.  But the signal was not strong enough where I wanted to use it, so I hooked up the WRT54G again.  I discovered that if I connected the U-Verse gateway to the "Internet" port on the WRT54G Linksys, then my home network was split in two, which I did not want.  The WRT54G access point is physically somewhat distant from my wired computer, so I wanted to keep the U-Verse gateway as the DHCP master. (The U-Verse gateway is a router with four "computer" ports but no "Internet" port.)
 
I followed instructions on the Linksys web site, and using my wi-fi connected computer I re-programmed the WRT54G to be "Disabled" as a DHCP server.  Then I powered down and physically connected the U-Verse gateway to a "Computer" port on the WRT54G.  This solved my problem:  my distant wi-fi computer now has a good signal, and both computers "see" each other.
 
However, now I seem to have lost access to the WRT54G setup "web page."  Is it possible to access the innards of the WRT54G when its DHCP service is disabled?  Or would I have to reset the device to factory configuration and start all over if I wanted to make any tweaks?