Removing the clutch master pin is a problem. Once out, you'll likely find the unhardened stock pin has a groove worn in it, which causes pin removal to be difficult. In addition, some cars had a pin with one e-ring and a head on the pin, instead of two e-rings. That means the pin can only move in one direction- and its not always in the 'easy' direction! Some owners cut a 1" hole in the side of the pedal box from the front trunk side, in line with the pin. This makes fiddling with the pin simpler, and you can lead the strongly suggested emergency front hood cable release thru the 1" pin access hole (see TBD Bulletin 9, Article 64).
When reassembling the master cylinder on a late '72-up with the clutch effort reduction system, ALL the unhardened links and pins in there may be similarly worn from age and utter lack of lubrication for 50 years. This critically reduces maximum clutch throw from pedal all the way back to the clutch disc. I used hardeneable tool steel and clips to fabricate all my replacement pins. The Pantera is truly a mechanic's (machinist's) car!