Two options for fixing the line, and both involve removing it.
You can remove it and have it repaired at a specialist shop that does hydraulic and pneumatic hoses and fittings. Or you can remove it and replace it with a new or used line.
Either way, have the system evacuated, cover the openings, and then go back to the shop that evacuated the system and have them pull a vacuum. Once that's done and all is well, have them refill the system.