Question heatsink nail broken :(

Probably not much danger, but also probably a good idea to replace it to keep it snug on top of the chip it cools. Since those things aren't easy to find, though, what to do...

I'd use two zip ties. Select a size that the length of it runs through the hole but the head doesn't. Run it through the board from top, then zip the head of the other one on from the bottom, snugging it up to the board. Then clip off the excess length of both of them. Problem solved. Don't try to tighten to much as those plastic pins don't hold it very tight any way.