Yea the factory's been spitting out a bad batch lately. I was able to screw mine down probably 4-5 times before it gave out... But as with reps, it's a gamble you might not need it at all.
But if you do, I did it myself it was pretty easy actually.. The parts cost me $54 from ofrei with shipping, then all you need it basic tweezer/needle nose pliers, marine epoxy ($5 from walmart), I also went ahead and greased everything with silicone grease to make the watch water-resistant.