These guys do a lowering kit for £15
http://www.cjaccessories.co.uk/home....cf68c6f3be0759
You replace the dog bones on the rear suspension linkage with slightly longer items (a few mm).
Anyone with a socket set and some spanners could fit them but for peace of mind I imagine any bike shop could do it for you. I could do it for you if you bring the bike and the parts to me.
Will it be a new bike? There might be warranty issues if not done by a suzuki dealer (if they even would).
If you don't want to mess around with suspension linkage you could have the seat reshaped.