First thanks to all who post here. I have learned much and saved a lot of money.

Recently I had to replace the fuel pump in my 97 Grand Caravan (I know, this is a Concorde forum, but read on). Everything I read pointed to removing the tank. This was bad news because it meant removing several old hoses (filler tube, EVAP lines, etc.) which made the job even worse (and more expensive because they can crack during removal).

The good news is that I was able to replace the fuel pump with the tank still installed in the vehicle. The key was making a low profile spanner wrench which allowed removal of the plastic lock ring while the fuel tank was still strapped to the vehicle. This link has detailed step-by-step instructions, pictures and a video;
Fuel Pump Lock Ring Wrench Socket for 2004 1995 Chrysler Dodge Plymouth | eBay

The wrench I made fits the lock ring on 1998-2004 Concorde too. I made a few extra to help you fix yours.

 

It also fits the 1999-2004 300M and the 1999-2001 LHS (3.5L 3497CC 215Cu. In. V6 GAS SOHC Naturally Aspirated).