You can clean it after you completely disasemble the gun and remove the stock. In most cases you just flush it out with a cleaning solution such as brake clean (non clorinated). There is a hole at the bottom that the cleaner tube will fit in and then with your cleaning rod you work the plunger and spring in and out from the receiver end. keep doing this until your cleaner runs out clear. Then LIGHTLY oil it and work the plunger in and out a few more time to distribute the oil. there is really no reason to remove the spring and plunger from the tube.
CPL holder since 1991, NRA Lifetime Member, DU Member, NICET certified
"For those who would give up essential liberty to purchase a little temporary safety, deserve neither Liberty nor safety.—Ben Franklin.”