Hopwall765

I tried to replace the fuel pump in my car. I could not get the return fuel line disconnected so that I could drop the tank. The 20 year old steel fuel line fastened to the underside of the car was rusty. I got the removal tool inserted into the connector coming from the tank. This line is stainless steel. I think I pulled the lines part way apart as I can see the raised ring on the rusty steel line. But I can't pull them apart. I can't push them back together either. I sprayed PB blaster and wire brushed before starting. Will compressed air help? The backup retention clip doesn't reinstall as I have it partly separated. Any suggestions?
The lines to the fuel filter came apart because the fuel filter housing was stainless. Car runs better with 20 year old fuel filter replaced.