What folk have said about reading up before hand (web), getting all the right bits (oil, foam washers etc) and taking your time. Two things I found useful:
For Fox forks you need (well it will make it much easier) a filed flat socket for the top nut – normal sockets are rounded and slip, I bought one (27mm I think) from TFT for a tenna or thereabouts.
Remember to let the air pressure out, assuming you have air forks. Otherwise when you release the bolt, the uppers will explode up into your garage ceiling.
Have fun and think of the money you’ll save 🙂