The tools you'll need are a jeweller's screwdriver and much smaller fingers than me. If you do things in the right order it should be a pretty quick repair.
The first thing you should do is make sure that the locking ring is rotating normally. I didn't do that and ended up having to re-attach the foot so that I could get enough leverage to move the ring. If the ring is locked up you can use a pair of pliers or a wrench to get it moving again. Be careful not to use too much force or you could cause more damage
|Next remove the four small screws at the base of the foot. Be careful not to tug the ribbon cable when removing the foot, and you will have to work with the cable attached so be careful not to damage it.|
|Inside the detached foot you will see a small circuit board. This is attached with four small screws. When you unscrew these, be very careful, as the locking pin on the shoe is spring loaded and you could lose the spring and the locking pin.|
Once you know what you are doing its a pretty simple repair to make and very inexpensive too. If you need spare parts contact the Nikon Spares department at email@example.com