So I was in a local store the other day looking at their stuff while I was waiting for my supplies to come in, and someone returned an unused badger hair brush because the knot was coming out of it. Manufacturing defect. I was looking at brushes already and the woman told me if I wanted the one with the defect I could have it for 5$... 90% off. I said sure, figuring I could somehow fix up a 50$ brush for less than 45$ and still come out ahead.

Anyways, to the point. The knot doesn't come all the way out, it's still in but it rotates and pops in and out of the handle when you apply any pressure. How would I go about fixing this? I assume I'll need to somehow take it out completely, clean the inside of the handle a bit, then glue it back in, but if someone could walk me through how to do it I'd be grateful

Oh, and the names of any materials, namely the epoxy or whatever else is used to glue the knot in.

Thanks in advance!