Someone had asked me to post some how-to pics of taking a magazine apart. This is an old mag I had laying around from a Sig P220. Most mags come apart the same way.
First, depress the button on the magazine base plate, which will allow the base plate to slide off.
Make sure you keep your thumb over the base plate, because the spring will want to launch it into the one place in the room where you'll need a coat hanger to fish it out Take note of which way the spring goes into the magazine. Sometimes it matters, sometimes it doesnt. This spring is tapered so it's pretty obvious.
Once you ease out the spring, you will now have all of the pieces out of the magazine (the follower will just fall out piece of cake)
Clean the pieces, and clean the empty mag. Try to clean up any oil you use so it wont attract too much gunk. Now, re-assemble the same way. Put the follower back in (it'll only fit the correct way). Then put the spring back in.
Now put the little button gizmo (sorry, forgot whats its called) over the spring, and compress it with your thumb so it sits flush.
Now just slide the base plate back on, making sure the button gizmo clicks back into place.
Thats it!! Some mags are tricker than others. Once you do this once or twice it will be a 5 or 10 second process.