Everyone,
Why hasn't anyone already helped this guy? I've only had my magazines for a few hours now.

Richard,
Come on, man! This is too easy. I've never tried to pull a magazine apart in my life and I had it figured out in about 2 minutes ;-) This is the method that worked for me.

1.) Compress the spring by pushing the follower down with a stick of some kind
2.) Take a thin rod (I used an allen key) and slide it through one of the holes in the sides of the mag, so that the some of the coils will stay compressed(just enough to take all the tension off the follower), but the rod is BELOW the follower. The follower should now be able to fall up and down in the top of the magaine and is easy to take out from the top. There is no real forcing needed, just rock the follower in the direction that it is willing to come out. Rock it sort of like you are unloading a round - down slightly and forward.
3.) Notice which way the spring goes in the magazine.
4.) Notice that the floorplate never comes off. I think the Detonics one is welded. The others I have are stamped down.
5.) If at any time you feel you are using anything other than the "gentle approach", then you are doing something different than I did.

Using this method, I was able to disassemble a factory Detonics mag, as well as 2 different designs of aftermarket mags (actually I didn't even use an allen key with the aftermarket ones, they were super easy). My original Detonics has no hole in the bottom, but my Aftermarket ones have either 1 or 3.

Hope this helps,
Cliff