well, not having the fob in my hands i couldnt tell you how to disassemble it, but even if you did, you would end up with a stub and noplace to attach it to a keyring. being just a stub, you wouldn't be able to turn the ignition because you wouldn't have leverage.
however, if you are deadset on removing the key from the fob, you pretty much have 2 options. a, take it to a locksmith where they will probably be able to remove it for you, or b, cut it off and drill a hole in it for the keychain. sorry i could be of more assistance.
6000k headlights, LED license plate fog lights, tinted taillights and to top it all off, 2 12" air horns!
the gf:'00impy 3.8, every option. COTM July 2013