How would you do it?

i replaced that line on my valiant and it was pretty easy. get a length of bailing wire to mock up the tube. get it in, bend it to shape and cut it to length while in place, then pull it out and you have a template to bend your new brake line with no worries of coming up short. you can do most of the bends by hand if you take your time. ofcourse you'll need a little tube cutter and a flaring tool with the correct fittings. and a bending plier if you're worried about kinks. good luck.