Question about the GSXR-600 Telefonica....?

Hey im a newbie so try not to bash this topic too much......

I'm 5'6'' ....and my buddy is selling his gsxr-600 telefonica moviestar, and I barely touch both feet........

Anyway to my question, Is it possible to lower the bike....like with the spring under just in front of the back tire...or how.. ...and how much can it be lowered.....w/o messing up the whole suspension/ride......

Thanks for any responses!