Seat belt removal
 

The car is a 1973 Lemans.

What is the best way to remove all of the seat belts in a car?

Which part did you have trouble with?

A Snap On T-50 Torx socket(the ONLY one that will take the torque required to break these loose), a breaker bar with a pipe for leverage, and a torch to heat them up if they are especially pesky...

Thank you both. I bought some parts off of someone that I need to go pick up. He sent me a message recently saying that if I needed the seat belts I would have to pull them myself. No big deal but I wanted to see how others have got them loose since the one time I tried I stripped out the bolt. Needless to say I just ordered the Snap-On tool.

Don't thank me, I didn't help yet!
Yes, if it's an original vehicle there's a good chance the belts have never been removed and the anchor bolts been in place 40 years. Give them a good soaking with something to penetrate the threads and try to keep any anchor bolts since they can be different shoulder types and hard to get now. Work them back and forth, retightening to free up the crusty threads, and resoak if needed. A torch can do the job, depends how much interior is around as to how suitable. A set of grips can be handy to put around the head if the torx bit has signs of wear, use both.