First, your Norinco isn't a real swell choice for a quick double.
First step is to slide the extractor in ans out of its bore and see if it binds. If it binds, inspect the shaft for stuff marks to find out why.
Next, slide a straight rod (about a foot long) into the extractor bore and a dowelling rod into the chamber and compair the axis of the two. Same idea is to slide a dowell into the chamber a see If the extractor drags on the dowell. If the extractor is not running the same axis as the chamber and drags on the cartridge, you may not be able to fix the problem and still have it extract.
To disable the extractor, you will have to cut the pushrod shaft (not a good plan)
You may or may not be able to remove enough material from the inner radius of the extractor to eliminate the interference with the cartridge. If you make a mistake, finding a replacement extractor will be a trick.
Have you considered just getting a TTN/Cimarron instead??
Coffinmaker