If so, was it horribly difficult? Could you explain to me how you did it?
Obviously this is a bit of a longshot. Ds2 snapped the bit you pull and it's left a sharp end. So I either replace the whole zip, or through away an otherwise OK grobag.
My local dry cleaners quote a price for replacing a zip that is just shy of the price of a new grobag. So at the moment, I'm agonising over whether to attempt to replace the zip myself, or just giving in and throwing the thing away.