>>96583176
Okay, this is only if your single germanium crystal core is actually cracked, not failed helium seals or other fixable normal stuff.

Charged cores can be jumped with a skeleton crew. First, you need to get word out via HPG or another ship. A crew is dispatched from whatever yard makes your model of ship. Best hope your core is still in production. They will slowly head toward your ship, one jump at a time, until they make it to you. That's when your new jump core is inserted into the spine of the ship and reconnected to all the important bits.

With super common models like the Invader, the front of the ship actually hinges up for this kind of replacement to get beyond the 500 year service life for the core.