Remove?!? I hope you meant "pull back"?? No need to remove the slip ring unless you're putting a free-float handguard on the rifle... IMHO, you should try to find yourself a decent set of the triangular handguards - they look best on the CQ-311. When I had one briefly a few years ago, I found a full set of furniture on Ebay (triangular handguards, A1 pistol grip, and old school M16 buttstock with no trap door) for a pretty decent price. I used all of the existing hardware and just replaced the OEM Norinco furniture with the newly acquired plastic... HTH's.
Cheers,
hsld.