Pop the dust cover off the end of the spindle (center of the wheel) with a screw driver between the inner edge and the drum, remove the cotter pin, back off the castle nut (ccw), reach around and grab the brake drum and gently pull it out away from the trailer 1/2" to one inch and then, with one hand catch the castle nut washer and outer wheel bearing as they come off the end of the spindle.
Continue removing the brake drum and set it gently on clean piece of cardboard or newpaper. Using a 12" wood dowel or section of old broom handle, reach the dowel pin through the hub opening on the outer drum into the center chamber and set it against the inner wheel bearing which is larger than the outer. Using a mallet gently stike the dowel pin to tap the inner wheel bearing and seal out. Strike the wheel bearing two or three times moving the dowel pin in 90* increments around the circumference of the bearing.
That doesn't look like a Nevr-Lube bearing to me. A Nevr-Lube is a pair of sealed bearings. That looks like one with a zerk fitting you use to put your grease gun on. That type works great of greasing the brake shoes and brake drums.