I assume "line" means metal
Just did mine this summer. If you have a lift, not too bad. On ramps, still doable. Mine were totally rusted out just in front of the rear wheel.

I removed the old ones (try not to bend too much). Then take your new line (mine was 5/16 from Napa; 25' is sufficient) and bend it to match the old. tape them together.

I didnt feel like messing with it all as one piece, so i made each part in 2 pieces, again cut right in front of the rear wheel. A compression fitting worked fine, and you could probably even splice them together with just a piece of rubber hose. The hardest part is re-clamping them; if your bends aren't quite right, that can be a problem. On the PITA scale 1-10, I'd say 5.

Do the brakes while your down there, too. Flare fittings a must.

__________________
Paul
2004 E500 4matic; 72,000mi