there's a set of master RA instructions somewhere on this forum. You can find the part information here water pump diagram. Only tool you need is a 10mm socket wrench. Your call as to whether you want to replace the thermostat or the temp sensor, or any of the hoses. More tips on my thread.

 

i am doing the thermostat as well. Do i absolutely need to remove the pulley directly underneath the water pump pulley to reach that bolt?

 

i ended up loosening that lower bolt with an open end wrench, to the point that it practicaly hit the back of the main pulley. i then pulled the water pump out with the bolt just sitting in the hole. if you need a little more clearance, you could loosen the main pulley bolts, so that it leans out a bit.

 

i have a brand new OEM thermostat for sale if anyone needs it
part number 11537586885

$50 shipped

 

No, use a short gear wrench. I just did a Range Rover. It uses the same 545 engine. Was not hard to do.