The Tapco mags can be disassembled rather easily for cleaning and maintenance should you like to play rough with your SKS.
I'm not advising you follow this method as you may break your Mag, but this is what i've done.
1- Down at the bottom of the mag there are two metal flaps that wrap up and around a plastic lip at the bottom. Take a pointed pick (something like an ice pick) and press it down in between the outermost part of the lip, and the vertical part of the flap - effectively what you'll do is compress the plastic part inward
2-after jamming the pick down side of it (you may have to use a hammer to get it in) take another flat head screw driver and insert it into the mag onto of the steel bottom plate. twist the screw driver and the side with the pick jammed into it should pop open.
3- once the one side is open, simply work the bottom plate back and forth and the other side will come off as well.
They are very tough glass filled nylon Mags - you can bend them and they wont break.
Once the mag is opened, just clean all the crud out, make sure the follower channel is clean, spay a little oil on the follower spring, and re assemble.
re-assembly is super easy, the bottom plate will slide on, and snap into place (you'll see what i mean when you get to this point).
I hope this is helpful for some of you!