you get two tophats in the kit. Take one and sit it on the workbench as if it was a top hat on someone’s head. Now file a notch, the size of a small pea, out of the top of it.
When you fit the two tophats to the NDS bearing you press one in from each side, so the notch is in the middle. When you come to remove the tophats, say when you need to swap out the bearings, you can get a screwdriver in the notch and tap the tophat out. Once you have one tophat out, then other is easy to tap out.
Without the notch, you can’t get anything in between the two tophats, so you’re stuffed. I filed two notches in mine, opposite each other, just to make it even easier to tap the tophat out. Just make sure the edges of the notch are smooth, so you don’t mark the crank axle with any burrs.