I need to replace the starter on my pathfinder, how easy/hard is it to remove and replace?

Hi Walter! It's not a novice job but it's not the worst job on the car. A lot depends on your mechanical ability. If you don't want to pick the brain of your local service manager, then you really should head to your local big box parts store and pick up the Chilton's for your Pathfinder. It's old enough now that you really should have one, especially if you are going to attempt this level of repair. Good luck!