How do I remove Matiz CV joint circlip?

Buried deep in the centre of the outer CV joint of the Matiz is a small circlip that holds the inner race of the joint onto the splines of the end of the shaft. How is it possible to spread that clip and thus remove the joint? I have tried circlip pliers, screwdrivers, allen keys and even resorted to trying to make a bespoke tool for the job. Eventually I cut the thing off with the judicious use of an angle grinder. Either I am missing something fundamental or there is a special tool for the job. Having got the old joint off the offside I can not fit the new joint for the same reason. I've still got the nearside to contemplate. Fine way to spend Father's Day!