Sorry for the first answer. According to the Bentley Service Manual, you need to pry off the cover with a screwdriver. A second screwdriver 180 degrees on the opposite side may be needed. Once the cover is off, you need to mark the position of the parts (joint and axle) before removing the circlip from the axle with circlip pliers. Be careful when removing the joint from the axle i.e. do not let any of the parts fall out.