Luckily it is not that hard to open it up and put it back together. I ordered a new spring, but I rode the bike for quite a while with the old one put back in before I changed it out. Unless the spring is broken I think you can just bend it out a little bit to add to it's "spring-i-ness" and put it right back in. Be careful not to damage the gasket on the cover when you open it. There are two little tabs, one on each side, meant to use with a screwdriver to pry the cover off. Smear a little oil on it before you close it back up and it won't leak. Let me know if you have any questions. I've done this twice this Summer, so I guess that makes me the current resident expert.
similar situation here....I bent the spring out a little an put it back in and have about 900 miles on it already with no issues. My gasket was destroyed upon removal, so I had to order a new one. Since I was waiting for parts, I ordered the spring as well, but the dealer accidentally ordered the other spring that goes on the shaft....maybe I will get that new sping on there over the winter, but I'm not having any issues. Before it "stuck in neutral" I had warnings of this coming, but was not aware of the solution. The warnings were, the bike seemed to "miss the gear" when shifting fast, but then recovered after down shifting.