How to completely remove custom input method (KeyMagic) in Language and Text on OS X

How to completely remove custom input method (KeyMagic) in Language and
Text on OS X

I install customised input method (KeyMagic 1.5) for KeyBoard Layout on OS
X Mountain Lion 10.8.4. It can deactivate uncheck but I want to completely
remove from input source list of Language and Text.
How to fix it.