First, make sure it's completely dry.
Second, check whether it has any rust-dirt-damage from electricity running while the water was inside the device.
Third, re-read Flashing N9.
Fourth, there is some mysterious N9/N950 Rescue CD.
Fifth, is it possible to ask for repair at a Nokia Service Centre if hardware is damaged? Water-damage is hardly covered by warranty, but still, they should have the best access to spare parts and repair tools.
Best wishes.