Steps:

1. Release the two retaining arms at the side of the drum. This will allow the cover to open and close freely.  keep hands and fingers clear of the spider and press the spring release button (the little button in the center of the drum). This is done to make sure there is no tension on the spring.  If there was tension on the spring you should have herd a loud metal grinding noise coming from the drum.  You might even see the spider (ammo holder in the drum) turn.

2. Next  with your right hand depress the spring release button located in the center of the drum.  With your left hand rotate the the spider clockwise ( about 3 turns) until the spider will tun no more and you see the magazine follower in the inner-most position. 

3.  Now load up all of the holes in the spider with bullets.   For testing prepuces you only need about five rounds however the drum will take all seventy five rounds if you need it to.

4.  Close the lid on the drum and reattach the two retaining arms on the sides of the drum.   With the left hand holding the drum use your right hand to wind the drum three complete turns clockwise.  Over turning of the drum can lead to malfunctions and a shorter magazine life.

5. You now have a fully loaded Norinco 75 round drum.   The drum now snaps into place just like any other magazine would and can be fired.   If you notice that the drum stops feeding rounds after a while try winding it some more.  It will be one of two things not enough power to load the next round in to the gun or your out of ammo.