Its pressed in mate
so are the lower ball joints
Have a look on ebay for ball joint press there not expensive

 

I've just done exactly the same job on my pathfinder.

G is right the ball joints are a pain to replace without a press - so I bought one!
The 21 pc £48 kit off eBay is huuuuge and has everything you could ever need, for any car really. You can also use it to change bushes (and press out or push in pretty much anything else)

 

cheers guys much appreciated that info, can you press them out whilst the wishbones are still on the vehicle

 

This might help:http://www.nissan-navara.net/45-d40...40-technical-library/18633-replacing-front-ball-joints-long-winded-i-board.html

 

Yes but the drive shaft gets in the way on the bottom one so you need to undo the hub and pull it out whilst keeping the driveshaft in the diff
If it comes out off the diff its not the end of the world it'll just open the oil seal and **** oil out