OP - your bike should have came with a bag of Kawi Tools in a pouch, sounds like you got gypped!

The Kawi P/N for the spring adjuster tool is 92110-1144. It looks like half of an open ended wrench with a little nipple on the end to grab the hook. As mentioned it is a pretty common tool and used to adjust those top two nuts easier, same type tool for a car coilover setup. There are two washers, one to set the preload and the other to lock the first one up. Make sure the lockwasher is broken loose or as mentioned, you'll never be able to move the bottom one. And make sure you retighten the top washer when you're done! Godspeed!

Cheers,

Anthony