Originally Posted by
kmart
You could also try wedging a Phillips head screwdriver or hex key between the stiff link's plates and twisting the key/screwdriver to force the plates apart slightly.
-1
The upper position on the chain tool was designed to resolve stiff links. The other option is to bend the chain with your hands back and forth. Don't do this on 10 speed chains.
http://en.wikipedia.org/wiki/Chain_tool