The body of your SB-600 is now in pieces (in case you weren't aware)! You can order parts from Nikon's parts department.

The reason I took mine apart is that it fell a few feet and wouldn't turn on afterwards. Well actually, I bought it off craigslist for $50 from someone who didn't know how to fix it. Anyways, the problem turned out to be that a couple of solder joints broke and the components came loose. The black box with F100 on it twisted sideways and one of its joints broke and it pushed the resistor beside it off the board. I swapped it out with one from my other SB-600 and it worked again!