How to replace part of rear brake line

There are many different lengths of brake line available as well as connection adapters to complete the repair... Most auto parts stores should have what you need, I know NAPA usually has a good inventory of brake line repair parts... Experienced parts counter personnel is hard to beat for knowledgeable parts look-up! .. Due to the 'brittle' nature of steel brake line, flaring is not recommended as it can be a difficult task even for a pro! .. You can remove all the line you need to replace and take it with you to parts store... Important note .. You might as well go ahead and see if the bleeder screws will loosen up now, got to bleed the brakes after line replacement, may need 'more' parts IF the bleeders are frozen//seized in place and won't turn! .. Good luck.