Upgrading the SSD in a Asus UX21A Zenbook

I'd like to upgrade the SSD in my Win 7 Asus UX21 Zenbook from 128 to 256 gb. From what I read, the UX21 (and UX31) used a nonstandard 18 pin card, so one either has to go for another ADATA XM11 ($70 "refurbished" on eBay) or use an adapter and get an m.2 card. Two questions:

- Anyone have experience succeeding in using an adapter and getting the combo to fit without altering the case, beyond perhaps a little tape on the inside? Which adapter?

- Cloning: If I used an adapter and m.2, then I assume cloning would be straight forward, using a USB 3.0 to 2.5” SATA III adapter cable. But if I went with the 18 pin ADATA XM11 itself, how could it be done?

Thanks,

 

The SSD in the UX21 is actually one of two versions of a Sandisk U100, 24x95 according to one site..