You don't. Buy new or good used seat belts. Don't try to fix them if they are not working.
It depends what is broken
$237
eBay.
Go to any parts supplier.
In a repair manual or online.
In a repair manual.
Do a Google search for it or buy a repair manual.
I'd suggest buying a repair manual.
I would start by purchasing a repair manual.
Auto manufacturers are not required to repair automatic seatbelts that are malfunctioning. Auto manufacturers are only required to make sure there is not a defect in the automatic seat belt mechanism.
You don't. The faulty line must be replaced.
It would help if you could say what the symptoms are.
There are many vacuum hoses, consult a repair manual.