Replace right front brake line - 2002 Pontiac Grand Prix

Depends if you are talking only the flex hose near the caliper (very easy), or the hard line (fairly difficult). The flex line just requires buying a new hose & bracket clips and bolting them on. I'm guessing the steel brake line corroded somewhere near the bottom of the firewall where mine did. I found it easier to just reroute the new line across the top of the firewall just under the hood gasket. It is very difficult, if not impossible to remove the line and replace it to the factory location without disturbing the other 3 brake lines.

My suggestion is to use a bolt culler and cut the line as far down the firewall as you can from above and then as far up the driver side firewall from underneath. Run the new line from the ABS module, across the top back of the engine compartment and then down the passenger front wheel well, and wrap it around the bottom of the wheel well to the factor bracket that holds the flex line. Use metal clips with the rubber lining to screw the brake line to the firewall and make sure it can't vibrate against anything. Use rubber hose around the brake line at any location that you can't avoid contact through vibration.

There's obviously a lot more to be said about how to bend brake line, make fittings, and bleeding brakes that I won't get into here because it sounds like the main question was how to tackle this tough fix. I would seriously consider thoroughly inspecting the other brake lines and the fuel line where they come up the firewall from under the car. I found several more locations just waiting to blow like my front right line did and decided to replace all the brake lines.