Nibs for the Galaxy Note 10.1 GT-N8013 (first edition, from 2013) are increasingly hard to find. An Internet search turns up a lot of tips that look like they're incompatible -- and indeed, they probably are.
It turns out that the nibs for this particular model are straight: no curves, no blobs -- just a tube of plastic with a rounded tip. A #2 Philips is included for scale:
And yes, you can just yank them out of the pen barrel.