When the Vaio Pro was released people marvelled over how Sony managed to put a reasonable computing power and airvent into such a tiny design. (Look at Apple's Macbook: it's more or less the same size but has no airvent (and thus will heat up) and has a laughable mobile processor.)
It was- like Sony Vaio Z's too- an impressive feat of engineering that had more to do with showing that than to actually making the laptop as good as possible (they could have made the laptop a little thicker and much more efficient). But people who bought it will love that razor sharp design, as do I.
Same case for the Vaio Z, it was never a sales topper but more a prestige product that showed how only Sony could cram that much power into a beautiful compact design, more powerful than many so-called high-end laptop competitors.
Do you really believe it is good idea to mess around with the insides of such piece? =)
If I were you, I would just send my laptop to Sony (you'll have to pay, but you'll restore your beautiful machine) and let them reinsert the old network card- or a new one suited for the Vaio Pro. If you really want a stronger rance, there are other external solutions for that too. Good luck!