Replacing a Towncar fuel filter

Caddyman, I have found the filter and begun to remove it. The forward end came off fine. The rearward end is set into some kind of rachet/flange arrangement. It looks like that in order to pull the old filter loose from that I have to depress flanges inside this little housing while pulling on the filter. The new filter came with clips. One type of these appears to depress the flanges,but apparently it doesn’t depress all of them,because I still can’t pull the old filter free. Any suggestions for getting this old filter free?