ORIGINAL: RIStrutStopper
The forearm nut is a bit of a pain, but I removed mine with a pair of needlenose pliers held open. I've got an old express mag too, if it wasn't for the M as the last character in the serial number, you wouldn't even know it was a magnum.
I tried that at first and damn near ruined the forearm tube and nut (years of gunk and rust). I decided to back-off and buy the tool from Midway before I really caused some damage [&:]