get the good packing
The hard part is breaking the packing nut open. I used the wrenches in the second link with extension pipe plus PB Blaster to them apart.I used a cheap pick too from an auto store and hemostats to pick the packing out. You can find good instructions for putting the new packing in. I got a 1" wooded dowl and cut two rings to fit around the dowl. You have to cut the rings at 90 degress so they overlap. When you install then stagger the joints by 180 degress. When the boat is in the water tighten the packing nut until is just stops leaking. Get the good almost dripless packing http://www.e-marine-inc.com/products/gfopacking/packing.htmlI would get these wrencheshttp://www.mahallmarketing.com/adjust_eze.html