How do I replace the magazine on my DDF5110500/DDF5120550 Gas Nailer? WARNING Injuries can occur due to accidental firing, ensure you remove the battery. Do not press the nose piece of the Gas Nailer against any surfaces. Keep your finger away from the trigger. Pull the lever used to unlock the magazine and remove the magazine itself. Insert the (new) magazine back into the slot (1) and push it into the magazine receptacle (2).