The easiest way to tell if a cartridge contains a moving magnet or a moving coil would be to do some research online, which would save you the hassle and potential heartbreak of opening up the cartridge and doing some expensive or even irreparable harm to it. If necessary, though, this is possible and can indeed be done by just about anyone, though the utmost care ought to be taken, lest you need to replace certain parts inside, which will be even more expensive in the case of a moving coil cartridge.