How to set-up my suspensions????

I've decided to chanqe my bike from my KDX 200 model 96 to a Yamaha WR 250 model 99. In fact, I have alredy bougth the new one. The only problem that I have is the suspensions. It's quit diferrent than the KDX, I don't feel they are working well while riding in rocks, moods or trail competitions, they are really hard. Most riders have told me that WR 250 have hard suspensions.
I need your help to try to set up the suspension of the WR 250 to feel it like the KDX or at least as close as possible. What can I do???

thanks..............