If leaking from that hose fitting there is a rubber o ring at the end and a teflon seal that are both known to cause issues. Try replacing those first. an 18mm wrench and a whole lot of cussing are in your future. Good luck. If the pump is old it may not be a bad idea to replace as they are fairly cheap and you have to bleed the system anyway.
Power steer pumps and leaks are my arch-nemesis... ugh.
I cant tell from the picture where the leak is occurring but that looks like its coming from the container for the fluid. The first thing I would check is to make sure you arent using normal power steering fluid. You need to use ATF(transmission fluid)