Wow, nobody's answered you? Well, I'm in your exact boat today due to an unfortunate incident with a micro/nano SIM adapter snagging on the extremely fragile SIM reader pins. A cursory glance at eBay suggests there still is a market for replacement Z2 SIM readers, but it would appear to require delicate soldering skills. If that doesn't sound like something you'd have the stomach for, perhaps a full board replacement (expensive!) is what you'll have to settle for.