From Jim these instructions

First of all, remove all the pipe work and wiring that is in the way of access to the pump, and then very carefully undo the two fuel pipes that are attached to the top of the pump via banjo unions.....don't let the copper washers fall away.....

Undo the 6 screws in the top the pump and carefully lift the top part away....the pump gaskets stay attached to the bottom. If you wish to clean the main pump part then depress the metal centre and rotate it 90 degrees. be careful, there's a spring behind the diaphram. In the top part of the pump, there is a plastic insert which can be removed from the metal part...this has the valves in it.

Re-assemble is pretty much the reverse....just remember to get the two fuel pipes the right way round, and to have the copper washers in either side of the banjo unions of the fuel pipes.

 Some comments and photos by Charles Weaver.

I took a fuel pump today apart to check out that ticking.

There are a couple of non return valves inside the pump, one of which breaks off, making the pump run at half power. At full throttle in top gear, this causes fuel starvation, and on this one I could not get above 100 mph.

The inside of the pump with the small strainer on the suction side.

Who knows where to get repair kits for these?
I am going to fix this one, then I have a spare, thus ensuring the one on the car will never fail.