My gosh, they are worth nigh on a $1,000 to a collector. Clean it and put it away or sell it and make a load of cash. Go buy a Ruger 10/22 or Henry for plinking.
Just remove the receiver cover by using a quarter to unscrew the receiver screws. Next unscrew the barrel lug retention screw on the bottom of the forend. Push the lug up from the bottom and the barrel will slide forward and free. Then give the bore a good cleaning with a rod, brush, and jag and patches. Wipe off every thing that you can get to in and out of the action but don't start knocking out pins (please). Do not lubricate the action. It is designed to run without lubrication.
Not sure about the 76 but the 66 has an ejector that falls free from the left side of the receiver once the receiver cover is removed. So, don't loose it. It is a bent flat piece of steel about an inch long.
Last edited by sheffieldshooter; September 30, 2012 at 10:02 PM.