The power steering pump on a land rover defender in underneath the alternator on the same self tightening belt which drives all the ancillarys on the front of the engine. to replace it i should think youd have to drain the power steering fluid and remove the belt or at least loosen it and remove the two pipes which go to the pump, then replace with new pump and fluid. are you sure its the pump thats wrong and not the steering box or a blockage in the pipes.
Dingo Dave, December 2007