Or you can pop a burst disk.
The burst disk pops from the inside, and you can't take the disk off without it becoming a bullet. I would not suggest trying. The disks are also on the marker side of the reg, meaning its only going to max out (if everything is working correctly) around 850 psi. You have two burst disks generally and ones a higher range, typically around 1.5-2 times the tank pressure and a lower disk, usually around 1.8k psi, both are way larger than the reg output.
If threads are destroyed the only things I would try:
Attempt to clean the threads and use a remote line like I said earlier or if the tank pressure is low enough to wear you can controllably press the reg pin and vent air manually you can do that. Please wear eye protection if you manually press the pin. Compressed air blown into your eyes can cause permanant damage, even at extremely low pressures.