I have put an after market black composite folding stock on my Norinco. It all went pretty smooth, except for the gas tube handguard removal and swap. I can't seem to get the pin out to switch handguards. I have put the gas tube in a vise and tried to take out the pin with a punch, but you can't get too aggressive with a hammer and vise for fear of damaging the gas tube. Anyone have any tips? I have thought about drilling this pin out and just replacing the pin, any thoughts? Thanks