I've been into the workshop and got the tool so I don't have to remember. It fits: BMW 3 Series E46, 5 Series E39, 7 Series E38, X5 3.0D, Vauxhall/Opal Omega-B, Freelander, Rover 75.
There are 2 bushes A & B (termed rings in the instructions), 1 extractor, 1 bolt. Because this tool fits many engines you have to vary it to suit each engine. The instructions state on some 'use with or without ring dependant on operation'. Also under Freelander it states 'short body may use A or B'. So there we have it, slightly useful but not completely.
Recap the job - Remove the bung in the casing, take the large nut off the pump shaft, [maybe don't fit any bush], screw on the extractor and nip it [no bolt is fitted to the extractor at this stage], NOW screw in the bolt until it contacts the the end of the pump shaft, [I think you can] support the extractor hexagon with a spanner whilst you tighten the bolt. 'CRACK' and the sprocket is released from the taper on the pump shaft. No Woodruff keys to worry about. Leave the extractor attached to stop the sprocket dropping. Maybe slip the bush on ready for assembly to aid alignment.
I didn't have any problems. Does this help?