To replace the seals do a [Search] on "seals".
For better handling you may, when you re-install the fork legs, slide the legs further up through the triple clamps; this steepens the steering angle and quickens the steering. Another thing many do here, including myself is replace the stock springs with Progressive fork springs. This doesn't neccessarily improve handling but it does help control fork dive and chassis attitude changes when braking.
Well. As far as replacing the seals, this seems to be the best thread..
http://www.gstwins.com/forum/viewtopic.php?t=7084
Good luck!
trey
Thanks for the info. I'll let you know how it goes.