2 pairs of pliers normally work for me. use a bit of heat, gas flame or suchlike to break the threadlock, if u still have problems.

careful when putting the new black one back on, its easy to break it as its so thin, and dont forget to use a bit of threadlock.

i would check the prices of the blue and black pinions against the pinions and clutch-bell as a complete unit (iirc its available like that) as i seem to remember theres not much difference and it saves the hassle or chance of breaking anything.

hth, good luck mate.