I have a 1998 Dodge Dakota 2x4 3.9 extended cab, one of my brake line rotted out. How hard is this to replace and can you get lines pre-bent? What would a shop charge to replace?

Buy stock tubing, double flaring tool, and a pipe bender and you should be able to replace anything you need. It's best to use metric flare nut wrenches on all connections. It's not hard--just take your time. Afterwards, bleed the complete brake system.