front shocks are non rebuildable. They are sealed units, no way to take them apart. nothing can be done with them.
Rears are fully rebuildable, any well known atv suspension shop should be able to revalve/respring them. As far as a "do it yourself kit", I am not aware of any. The only kits that I know off that allows a person to do there own shock valving for bikes or quads are the Race Tech Gold Valves. Unfortunately, they don't make the kits for the rear shocks on the 700XX. You might be able to call a suspenison shop and see if they will send you the shims and parts for revalving, but if you have never taken a shock apart before, I would recomend having an experienced person show you what to do.
Doug