You can get parts at the Sears Canada site.
The dripping is likely from a loose tubing connection somewhere between the water tank and the freezer door where it dispenses. The usual place to look is the fitting under the freezer door hinge, since many installers remove the doors to get the unit into the house and forget to secure those connections.. If these connections are not secure, air gets into the water line and causes it to drip on. Also check the connections where the tubing attaches to the water valve. In fact you can manually follow the tubing all thru the unit to check any fittings. If no loose connections are discovered, a new water valve may be in your future.
The water filter simply unscrews from the kickplate and pops right out. Since we are not Canadian, we don't offer parts resources for Canadians, but I'm sure you have options in your area for parts.