[johnsjmc]

It,s routine to repair rusty fuel lines with sections of fuel injection rated hose. The Lesabre is probably rusted out under the firewall /front seat area.
There is a special hose clamp available which doesn,t cut into the hose like an ordinary gear type clamp does. No need to drain the tank The fuel pump won,t be running and only a small amount of fuel will leak out when the line is cut. .Use a small tube cutter ,not a hack saw blade.