Any time the bearing is removed (opened), the grease needs to be replaced, especially if the seals are removed. This is because it's hard to breach the grease charge without contaminating the grease. It is imperative to NOT allow the grease to get contaminated. This includes metal burrs, brake dust, anything. When you wash out the old grease, any contaminants will get washed out also.
There is no such thing as a quick visual inspection of the wheel bearings. You either leave it alone or properly repack the bearing.
I think I used a crowbar to remove my seals. When I reinstalled the seal I put a flat piece of plate steel over the seal and hammered it down. Using a press is the superior method.
Don't forget to properly set the axial preload on the bearing. This has a significant effect on bearing life.
95 E320 Cabriolet, 131K