Changing C5 spheres

[StevieOMG]

I've decided I need to change my spheres. LX with 130k on. Whilst the spheres seem reasonably easy to obtain, a removal tool does not. Anyone have any recommendations as to where to get one and any how to guide available? I know there are only four (two front and two rear). I'm assuming that front are reasonably easy as being under the bonnet they stay clean but not so with the rear.

Any advice gratefully received.

[Lighty]

I have the proper Citroen sphere tool, it is rubbish, and rarely removes them, as it is just not strong enough. I have a Hugh chain wrench, and this removes ANYTHING with a thread