easyier to take off the whole pump,should slide out easily.
once you have done this remove front cover,remove impellor,2 screwdrivers and prise out impellor.
next will have to destroy lipseal to get it out but easy to find replacement,need again two implements to prise out lip seal,i have 2 files that have the pointy ends bent over to form a hook,should come out easily.
next measure id and od of seal and shaft,find the local SKF bearing dealer will have a standard lip seal,once you have found the correct seal buy a few spares.
also inside the lip seal is a spring,this for marine
applications is stainless,a normal auto motive spring is probabl mild steel
which will rust,this you need to replace with an o,ring,also from skf dealer,make sure it is a snug fit replace spring with the oring.
also check the bearings on the back side of the pump housing if worn replace but will need a press,will be another lipseal on the engine side of things,should cost max $20,seals about $3 a piece