These Mec-Gar 18+2’s…how in the bloody hell do you take them apart???
forgive my ignorance…
look at back of mag where the extension is. There should be a rectangular hole in a piece of metal. Put your fingernail in the slot and pull up then you can remove extension.(this is from memory as i am not at home right now. I hope I remember right)
OMFG!!!
YOU ROCK!!! 
im such a dumbass lol!