You don't need a spudger to remove a topcase from an A1181. I don't even own a spudger. They are mostly useful for iPhones, iPads, unibody screen glass removal, etc., but I don't use them at all for day-to-day laptop repair. A good pair of tweezers is far more useful.
To remove the topcase from an A1181, once all the screws are out, pull it up slightly from the back by the screen, then grip the left and right edges at the same time, and shimmy it up and down and side-to-side, applying pressure upwards. Sort of like the motion of a boat rocking back and forth. You can also press upward from inside the empty battery compartment. The main thing is you want to keep the topcase horizontal and avoid lifting any end of it too far upward, because you will bend the metal pieces holding it in, which will make it harder to remove.
Be patient, and after a minute of moving the topcase around as described (while keeping it horizontal) the left and right sides will release.