HORI EX2’s and their brethren (DOA4, SC4) are wretched things - I cannot stress this enough. Aside from the poor quality of the shell, stock parts, and design, the PCB is also a disgrace - it’s not common ground, contact points will break at the slightest button stress or applied heat, and it’s huge.
If all you want to do is swap buttons & joystick around, then the easiest solution, as already stated, is the Mad Catz SF4 SE stick (coincidentally, in the UK they’ve just been selling these for 20 on PS3 and 25 on 360).
The Datel 360 & PS3 stick is very cheap and easy to modify with Sanwa/Seimitsu parts (even more so with Korean Crown buttons), and only takes a small amount of effort.
But Christ, even for $30, EX2’s are not worth the short term & long term hassle.