There is a special tool available for holding the injector pump sprocket (and therefore the timing), in place without the need to remove the timing gear. Otherwise, the timing belt has to be removed, then the belt sprocket (3 x 10mm head bolts) - don't undo the centre nut. Disconnect fuel lines, injector pipes, (you will have to remove them entirely), throttle cable, fuel cut-off switch, boost pipe, spill rail pipe, rear pump support bracket, and finally the 3 x 13mm nuts that hold the pump to the rear of the timing case.
The pump will then lift away.
Les.